Method and apparatus for managing adaptation layer of relay between terminals in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Such a method performed by a relay UE for user equipment (UE)-to-UE (U2U) sidelink communication in a wireless communication system comprises the steps of: obtaining configuration information for a sidelink relay adaptation protocol (SRAP); and receiving an SRAP protocol data unit (PDU) from the first UE by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs) based on the configuration information, wherein the SRAP PDU is received by the relay UE by using a radio link control (RLC) channel shared by the plurality of SL SRBs.

Description

Technical Field

[0001] The present disclosure generally relates to a wireless communication system, and more particularly, to a method and apparatus for managing an adaptation layer of a terminal relay in a wireless communication system. Background Art

[0002] 5G mobile communications technology defines a wide frequency band to enable high transmission rates and new services, and can be implemented not only in "sub-6 GHz" frequency bands such as 3.5 GHz, but also in ultra-high frequency ("above 6 GHz") frequency bands known as millimeter waves (such as 28 GHz and 39 GHz). Furthermore, consideration is being given to implementing 6G mobile communications technology (referred to as "beyond 5G systems") in the terahertz frequency band (e.g., the 95 GHz to 3 THz band) in order to achieve transmission rates fifty times faster than 5G mobile communications technology and ultra-low latency that is one-tenth that of 5G mobile communications technology.

[0003] In the early stages of 5G mobile communications technology, to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC), ongoing standardization involves technologies such as beamforming and massive MIMO to mitigate radio wave path loss and increase radio wave transmission range in millimeter waves, parameter sets for dynamic operation of time slot formats (for example, operation of multiple subcarrier spacings) for efficient utilization of millimeter wave resources and timeslot formats, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods (such as LDPC (low-density parity-check) codes for large-capacity data transmission and polar codes for highly reliable transmission of control information), L2 pre-processing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, in view of the services supported by 5G mobile communication technology, discussions are underway on the improvement and performance enhancement of initial 5G mobile communication technology, and standardization is already underway at the physical layer involving technologies such as: Vehicle-to-Everything (V2X) technology designed to assist autonomous vehicles in making driving decisions and improve user convenience based on information transmitted by vehicles about the vehicle's location and status, New Radio Unlicensed (NR-U) technology designed to operate systems that comply with various regulatory requirements in unlicensed frequency bands, NR UE energy-saving technology, Non-Terrestrial Network (NTN) technology for UE-satellite direct communication that provides coverage in areas where terrestrial network communication is unavailable, and positioning technology.

[0005] Furthermore, in the area of ​​radio interface architecture / protocols, ongoing standardization involves technologies such as: Industrial Internet of Things (IIoT) technologies for supporting new services through interoperability and integration with other industries; IAB (Integrated Access and Backhaul) technologies for providing nodes for expanding network service areas by integrating wireless backhaul links and access links; mobility enhancement technologies including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (2-step RACH for NR) for simplifying the random access process. Standardization is also ongoing in the area of ​​system architecture / services, involving technologies such as: 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software-defined networking (SDN) technologies; and mobile edge computing (MEC) technologies for receiving services based on UE location.

[0006] If this 5G mobile communication system is commercialized, the already exponentially growing number of connected devices will be connected to the communication network, and it is expected that the functionality and performance of the 5G mobile communication system and the integrated operation of connected devices will need to be enhanced. To this end, new research is planned for the following: to effectively support extended reality (XR) such as augmented reality (AR), virtual reality (VR), and mixed reality (MR); to improve 5G performance and reduce complexity by utilizing artificial intelligence (AI) and machine learning (ML); support for AI services; support for metaverse services; and drone communications.

[0007] Furthermore, this development of 5G mobile communication systems will not only lay the foundation for the development of new waveforms for ensuring coverage in the terahertz band for 6G mobile communication technology, full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies (such as array antennas and large antennas), metamaterial-based lenses and antennas for improving the coverage of terahertz band signals, high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS); it will also lay the foundation for the development of full-duplex technologies for increasing the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technologies for achieving system optimization by leveraging satellites and AI (artificial intelligence) and internalizing end-to-end AI support functions at the design stage, and next-generation distributed computing technologies for realizing services with a complexity level that exceeds the operational capabilities of UEs by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] Technical issues

[0009] The present disclosure provides a method and apparatus for managing an adaptation layer of a terminal relay in a wireless communication system so as to provide a service using the terminal relay.

[0010] The technical subject matter pursued in the present disclosure may not be limited to the above-mentioned technical subject matter, and other technical subject matter not mentioned herein may be clearly understood by those skilled in the art to which the present disclosure relates through the following description.

[0011] Problem Solution

[0012] A method performed by a relay UE for user equipment (UE) to UE (U2U) sidelink communication in a wireless communication system may include: acquiring configuration information about a sidelink relay adaptation protocol (SRAP); and receiving an SRAP protocol data unit (PDU) from a first UE by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs) based on the configuration information, wherein the SRAP PDU is received by the relay UE using a radio link control (RLC) channel shared by the plurality of SL SRBs.

[0013] A relay UE for user equipment (UE) to UE (U2U) sidelink communication in a wireless communication system may include: a transceiver; and a controller coupled to the transceiver, wherein the controller is configured to: obtain configuration information about a sidelink relay adaptation protocol (SRAP); and receive an SRAP protocol data unit (PDU) from a first UE by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs) based on the configuration information, wherein the SRAP PDU is received by the relay UE using a radio link control (RLC) channel shared by the plurality of SL SRBs.

[0014] A method performed by a first user equipment (UE) in a wireless communication system may include: obtaining configuration information about a sidelink relay adaptation protocol (SRAP); and based on the configuration information, sending an SRAP protocol data unit (PDU) to a relay UE for UE-to-UE (U2U) sidelink communication by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs), wherein the SRAP PDU is received by the relay UE using a radio link control (RLC) channel shared by the plurality of SL SRBs.

[0015] A first user equipment (UE) in a wireless communication system may include: a transceiver; and a controller coupled to the transceiver, wherein the controller is configured to: obtain configuration information about a sidelink relay adaptation protocol (SRAP); and send an SRAP protocol data unit (PDU) to a relay UE for UE-to-UE (U2U) sidelink communication by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs) based on the configuration information, wherein the SRAP PDU is received by the relay UE using a radio link control (RLC) channel shared by the plurality of SL SRBs.

[0016] Advantageous Effects of the Invention

[0017] According to an embodiment of the present disclosure, an apparatus and method capable of efficiently providing a service in a wireless communication system may be provided.

[0018] Advantageous effects that can be obtained from the present disclosure may not be limited to the above-mentioned effects, and other effects not mentioned herein may be clearly understood by those skilled in the art to which the present disclosure pertains through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flowchart of a process for establishing a PC5 unicast link for direct communication between UEs according to an embodiment of the present disclosure is shown.

[0020] Figure 2 A wireless protocol structure of a UE-to-network (U2N) relay according to an embodiment of the present disclosure is shown.

[0021] Figure 3 A flowchart illustrating a process in which a base station configures an adaptation layer of a UE-to-network (U2N) relay according to an embodiment of the present disclosure is shown.

[0022] Figure 4 A wireless protocol structure of a UE-to-UE (U2U) relay according to an embodiment of the present disclosure is shown.

[0023] Figure 5 A flowchart of a process for establishing a PC5 unicast link for UE-to-UE (U2U) relay according to an embodiment of the present disclosure is shown.

[0024] Figure 6 A flowchart of a process for acquiring a local identifier (local identity) of a UE-to-UE (U2U) relay from a base station according to an embodiment of the present disclosure is shown.

[0025] Figure 7A flow chart is shown for configuring an adaptation layer for an end-to-end (E2E) sidelink signaling radio bearer (SL-SRB) relay for a UE-to-UE (U2U) relay using a specific configuration according to an embodiment of the present disclosure.

[0026] Figure 8 A flow chart is shown for configuring an adaptation layer for an end-to-end (E2E) sidelink signaling radio bearer (SL-SRB) relay for a UE-to-UE (U2U) relay using a specific configuration according to an embodiment of the present disclosure.

[0027] Figure 9 A flowchart of a process for establishing an end-to-end (E2E) sidelink data radio bearer (SL-DRB) for a UE-to-UE (U2U) relay and configuring an adaptation layer for the sidelink data radio bearer relay according to an embodiment of the present disclosure is shown.

[0028] Figure 10 The internal structure of a base station according to an embodiment of the present disclosure is shown.

[0029] Figure 11 The structure of a UE according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0031] In the process of describing the embodiments, descriptions related to technical contents well-known in the relevant field and not directly related to the present disclosure will be omitted. Such unnecessary omissions are to prevent the main idea of ​​the present disclosure from being obscured and to convey the main idea more clearly.

[0032] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted or schematically shown. In addition, the size of each element does not fully reflect the actual size. In the corresponding drawings, the same or corresponding elements are assigned the same reference numerals.

[0033] By reference to the embodiments described in detail below in conjunction with the accompanying drawings, the advantages and features of the present disclosure and their implementation will be apparent. However, the present disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to fully disclose the present disclosure and inform those skilled in the art of the scope of the present disclosure, and the present disclosure is limited only by the scope of the appended claims. Throughout the entire specification, the same or similar figure marks indicate the same or similar elements. In addition, when describing the present disclosure, when it is determined that the description may make the subject matter of the present disclosure unnecessarily unclear, the detailed description of the known functions or configurations incorporated herein will be omitted. The terms to be described below are terms defined in view of the functions in the present disclosure and may be different according to the user, the user's intention or custom. Therefore, the definition of the terms should be determined based on the content throughout the entire specification.

[0034] The following detailed description of the embodiments of the present disclosure is mainly directed to the new RAN (NR) as the radio access network and the packet core as the core network (5G system, or 5G core network, or next generation core (NG core)) in the 5G mobile communication standard specified by the Third Generation Partnership Project (3GPP) as a mobile communication standard organization, but based on the determination of those skilled in the art, the main ideas of the present disclosure can be applied to other communication systems with similar backgrounds through some modifications without significantly departing from the scope of the present disclosure.

[0035] In the following description, for convenience, some terms and names defined in 3GPP standards (standards for 5G, NR, LTE, or similar systems) may be used. However, the present disclosure is not limited to these terms and names and can be applied in the same manner to systems conforming to other standards.

[0036] In the following description, for convenience and explanation, terms for identifying access nodes, terms for referring to network entities, terms for referring to messages, terms for referring to interfaces between network entities, terms for referring to various identification information, etc. are used. Therefore, the present disclosure is not limited to the terms used herein, and other terms referring to subjects having equivalent technical meanings may be used.

[0037] In the following description, a base station is an entity that allocates resources to a terminal and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a wireless access unit, a base station controller, and a node on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. In this disclosure, "downlink (DL)" refers to a radio link via which a base station transmits signals to a terminal, and "uplink (UL)" refers to a radio link via which a terminal transmits signals to a base station.

[0038] In this document, it should be understood that each block of the flowchart diagram and the combination of blocks in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can instruct the computer or other programmable data processing device to operate in a specific manner so that the instructions stored in the computer-usable or computer-readable memory produce an article including an instruction device, which implements the functions specified in the one or more flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device, thereby generating a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flowchart blocks.

[0039] In addition, each block in the flowchart illustration may represent a code module, code segment, or code portion, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may occur out of order. For example, depending on the functionality involved, two blocks shown in succession may actually be executed approximately simultaneously, or the blocks may sometimes be executed in reverse order.

[0040] As used in the embodiments of the present disclosure, the term "unit" refers to a software element or hardware element that performs a predetermined function, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), and a "unit" can perform certain functions. However, the term "unit" is not always limited to software or hardware. A "unit" can be configured to be stored in an addressable storage medium or to execute one or more processors. Thus, a unit includes, for example, a software element, an object-oriented software element, a class element, or a task element, a process, a function, an attribute, a procedure, a subroutine, a program code segment, a driver, firmware, microcode, circuits, data, a database, a data structure, a table, an array, and parameters. The elements and functions provided by a "unit" can be combined into a smaller number of elements or "units" or divided into a larger number of elements or "units." Furthermore, elements and "units" can be implemented as one or more CPUs within a playback device or a secure multimedia card. Furthermore, a "unit" in the embodiments may include one or more processors.

[0041] 5G mobile communications technology defines a wide frequency band, enabling high transmission rates and new services. It can be implemented not only in frequency bands "below 6 GHz," such as 3.5 GHz, but also in frequency bands "above 6 GHz," known as millimeter waves (such as 28 GHz and 39 GHz). Furthermore, consideration is being given to implementing 6G mobile communications technology (referred to as "beyond 5G systems") in terahertz frequency bands (e.g., the 95 GHz to 3 THz band) in order to achieve transmission rates fifty times faster than 5G mobile communications technology and ultra-low latency that is one-tenth that of 5G mobile communications technology.

[0042] In the early stages of 5G mobile communications technology, in order to support services and meet the performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC), ongoing standardization involves technologies such as beamforming and massive MIMO for mitigating radio wave path loss and increasing radio wave transmission range in millimeter waves, parameter sets for dynamic operation of time slot formats (for example, operating with multiple subcarrier spacings) for efficient utilization of millimeter wave resources, initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods (such as LDPC (low-density parity-check) codes for large-capacity data transmission and polar codes for highly reliable transmission of control information), L2 preprocessing, and network slicing for providing dedicated networks dedicated to specific services.

[0043] Currently, discussions are underway on improvements and performance enhancements to initial 5G mobile communication technologies in view of the services they are to support, and there is already physical layer standardization on technologies such as: Vehicle-to-Everything (V2X) technology that assists autonomous vehicles in making driving decisions and improves user convenience based on information transmitted by vehicles about their location and status, New Radio Unlicensed (NR-U) technology designed to enable system operation to comply with various regulatory requirements in unlicensed frequency bands, NR UE energy saving technology, Non-Terrestrial Network (NTN) technology as UE-satellite direct communication for providing coverage in areas where terrestrial network communications are unavailable, and positioning technology.

[0044] Furthermore, in the area of ​​radio interface architecture / protocols, technologies undergoing standardization include: Industrial Internet of Things (IIoT) technologies for supporting new services through interoperability and integration with other industries; IAB (Integrated Access and Backhaul) technologies for providing nodes for expanding network service areas by integrating wireless backhaul and access links; mobility enhancement technologies including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (2-step RACH for NR) technologies for simplifying random access procedures. Standardization is also ongoing in the area of ​​system architecture / services, involving technologies such as a 5G baseline architecture (e.g., a service-based architecture or service-based interface) for combining network function virtualization (NFV) and software-defined networking (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0045] If this 5G mobile communication system is commercialized, the already exponentially growing number of connected devices will be connected to the communication network, and it is expected that the functionality and performance of the 5G mobile communication system and the integrated operation of connected devices will need to be enhanced. To this end, new research is planned to include: Extended Reality (XR) for effectively supporting augmented reality (AR), virtual reality (VR), mixed reality (MR), etc.; improving 5G performance and reducing complexity by utilizing artificial intelligence (AI) and machine learning (ML); AI service support; proto-universe service support; and drone communication.

[0046] Furthermore, this development of 5G mobile communication systems will not only lay the foundation for the development of new waveforms for ensuring coverage in the terahertz band for 6G mobile communication technology, full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies (such as array antennas and large antennas), metamaterial-based lenses and antennas for improving the coverage of terahertz band signals, high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), but will also lay the foundation for the development of full-duplex technologies for increasing the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technologies for achieving system optimization by leveraging satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technologies for realizing services with a complexity level that exceeds the operational capabilities of UEs by utilizing ultra-high-performance communication and computing resources.

[0047] Hereinafter, the present disclosure relates to a method and apparatus for managing an adaptation layer (Sidelink Relay Adaptation Layer (SRAP)) for inter-UE relay. Specifically, when a UE supporting inter-UE relay is to configure inter-UE relay via a target UE and a relay UE, it may be necessary to distinguish between data sent by the source UE to the target UE and data sent to the relay UE. For example, data sent to the target UE and data sent to the relay UE can be distinguished by a PC5 relay RLC channel corresponding to a sidelink radio bearer (SLRB) determined by the adaptation layer of each UE. The source UE can configure the adaptation layer to determine the PC5 relay RLC channel, through which the SL-SRB or SL-DRB to be sent to the target end can be sent to the relay UE. The source UE can send configuration information about the adaptation layer to the relay UE.

[0048] The relay UE may configure the adaptation layer to identify a PC5 relay RLC channel, over which the SL-SRB to be sent from the source UE to the target UE is transmitted to the relay UE. The relay UE may send configuration information regarding the adaptation layer to the source UE. The relay UE may configure the adaptation layer to identify a PC5 relay RLC channel, over which the SL-SRB or SL-DRB to be sent from the source UE to the target UE is transmitted to the target UE. The configuration information regarding the adaptation layer may be sent to the target UE.

[0049] The relay UE may identify or determine the target UE via the PC5 relay RLC channel and the adaptation layer configuration information of the data received from the source UE, and determine the PC5 relay RLC channel for transmission to the target UE. The target UE may identify or determine the source UE via the PC5 relay RLC channel and the adaptation layer configuration information of the data received from the relay UE, and identify or determine the corresponding SLRB.

[0050] According to an embodiment of the present disclosure, the source UE may configure an adaptation layer to transmit a message through a PC5 relay radio link control (RLC) channel, the message belonging to a sidelink signaling radio bearer (SL-SRB) or a sidelink data radio bearer (SL-DRB) to be transmitted to the target UE via the relay UE, and may transmit configuration information of the adaptation layer to the relay UE. Alternatively, the relay UE may configure an adaptation layer to relay the SL-SRB transmitted by the source UE to the target UE, and may transmit configuration information of the adaptation layer to the source UE. The relay UE may transmit configuration information of the adaptation layer configured by the source UE or the relay UE to the target UE. When the target UE receives data from the relay UE, the target UE may determine, based on the adaptation layer, that the data has been relayed from the source UE via the relay UE, and may determine to which SL-SRB or SL-DRB the data belongs. For UE relay services, each UE may support UE relay via configuration of the adaptation layer and transmission of configuration information.

[0051] Figure 1 A flowchart of a process for establishing a PC5 unicast link for direct communication between UEs according to an embodiment of the present disclosure is shown.

[0052] refer to Figure 1 According to an embodiment, UE1 110 and UE2 120 may establish a direct connection via a sidelink interface. For example, UE1 110 and UE2 120 may be configured to be directly connected via a sidelink interface. UE1 110 and UE2 120 may be referred to as UEs capable of sending and / or receiving data and signaling via a direct connection.

[0053] According to an embodiment, in operation 101, UE1 110 may send a direct communication request message to UE2 120 to establish a PC5 unicast link. If UE2 120 receives the direct communication request message of operation 101, in operation 102, UE2 120 may perform PC5 security configuration, such as mutual authentication and encryption key configuration, for the PC5 unicast link to UE1 110. For example, in operation 102, UE2 120 may initiate or perform PC5 security configuration in response to receiving the direct communication request message.

[0054] According to an embodiment, if it is determined that mutual authentication, encryption key configuration, etc. for establishing a direct connection between UE1 110 and UE2 120 have been performed normally, UE2 120 may transmit a direct communication accept message to UE1 110 in operation 103, and PC5 unicast link establishment may be completed. UE1 110 and UE2 120 may perform direct communication configuration via PC5 radio resource control (RRC).

[0055] According to an embodiment, in operation 104, signaling (message or information) for exchanging sidelink UE capability information may be transmitted in the PC5-RRC layer of UE1 110 and UE2 120. In operation 107, signaling for exchanging configuration information of SLRBs used for data transmission and reception may be transmitted in the PC5-RRC layer of UE1 110 and UE2 120. The SL-SRB used for transmitting the signaling exchanged between UE1 110 and UE2 120 in operations 101, 102, 103, 106, and / or 107 may correspond to SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3. Configuration information of SL-SRB0, SL-SRB1, SL-SRB2, and / or SL-SRB3 may be stored in UE1 110 and UE2 120 as a designated configuration. The specified configuration information of the SL-SRB may be as shown in [Tables 1-1, 1-2, 1-3, and 1-4]. For example, the specified configuration information of the SL-SRB may be [Table 1-1], [Table 1-2], [Table 1-3], and / or [Table 1-4].

[0056] [Table 1-1]

[0057] 9.1.1.4 SCCH Configuration

[0058] Parameters specified for unicast NR sidelink communications, which are used for the sidelink signaling radio bearer of PC5-RRC messages. The SL-SRB using this SCCH configuration is named SL-SRB3.

[0059]

[0060] [Table 1-2]

[0061] Parameters specified for NR sidelink communications, which are used for sidelink signalling radio bearers for unprotected PC5-S messages (e.g. Direct Link Setup Request, TS 24.587

[57] , or Prose Direct Link Setup Request, TS 24.554

[72] ). The SL-SRB using this SCCH configuration is named SL-SRB0.

[0062]

[0063] [Table 1-3]

[0064] Parameters specified for unicast NR sidelink communications, which are used to establish the sidelink signalling radio bearer for PC5-S security messages (e.g. Direct Link Security Mode Command and Direct Link Security Mode Complete, TS 24.587

[57] , or ProSe Direct Link Security Mode Command and ProSe Direct Link Security Mode Complete, TS 24.554

[72] ). The SL-SRB using this SCCH configuration is named SL-SRB1.

[0065]

[0066] [Table 1-4]

[0067] Parameters specified for unicast NR sidelink communications for sidelink signalling radio bearers with protected PC5-S messages other than Direct Link Security Mode Complete, TS 24.587

[57] , or Prose Direct Link Security Mode Complete, TS 24.554

[72] . The SL-SRB using this SCCH configuration is named SL-SRB2.

[0068]

[0069] Three examples of a method in which the UE1 110 and the UE2 120 acquire sidelink data radio bearer (SL-DRB) configuration information corresponding to data in operation 107 are shown in [Table 2].

[0070] [Table 2]

[0071] If UE1 110 or UE2 120 is a transmitting (Tx) UE, UE1 110 or UE2 120 may obtain configuration information for the SLRB for the QoS flow corresponding to the data to be transmitted based on one of the three methods in [Table 2]. In operation 107, UE1 110 or UE2 120 may transmit the SLRB configuration information for the QoS flow to UE2 120 or UE1 110, which corresponds to a receiving (Rx) UE, via PC5-RRC layer signaling. For example, if UE1 110 is a transmitting UE, UE2 120 may be a receiving UE, and if UE2 120 is a transmitting UE, UE1 110 may be a receiving UE. In the present disclosure, a transmitting UE and a receiving UE may be referred to as a UE configured to transmit data at a specified time and a UE configured to receive data, respectively. Therefore, a transmitting UE may also be configured to receive data, and a receiving UE may also be configured to transmit data.

[0072] The SLRB configuration information to be applied when the receiving UE receives the QoS data flow may be determined by the receiving UE itself. UE1 110 and UE2 120 may apply the SLRB configuration information for data configured in operation 107 and transmit and / or receive data in operation 108.

[0073] Figure 2 A wireless protocol structure of a UE-to-network (U2N) relay according to an embodiment of the present disclosure is shown.

[0074] refer to Figure 2 , the wireless protocol of the U2N relay may be composed of Uu-SDAP or Uu-RRC 211, Packet Data Convergence Protocol (Uu-PDCP) 212, PC5-SRAP 213, PC5 Radio Link Control (RLC) 214, PC5 Medium Access Control (MAC) 215, and / or PC5-PHY 216 in the remote UE 210, may be composed of PC5-SRAP 221, PC5-RLC 222, PC5-MAC 223, PC5-PHY 224, Uu-SRAP 225, Uu-RLC 226, Uu-MAC 227, and / or Uu-PHY 228 in the relay UE 220, and may be composed of Uu-SDAP or Uu-RRC 231, Uu-PDCP 232, Uu-SRAP 233, Uu-RLC 234, Uu-MAC 235 and / or Uu-PHY 236. In the present disclosure, the term “may consist of…” may be replaced with “may include.” For example, the wireless protocol of the U2N relay may include Uu-SDAP or Uu-RRC 211 in the remote UE 210, Uu-PDCP 212, PC5-SRAP 213, PC5-RLC 214, PC5-MAC 215, and / or PC5-PHY 216.

[0075] According to an embodiment, the functions of the Uu-SDAPs 211 and 231 may include at least some of the following functions.

[0076] - Mapping between QoS flows and data radio bearers

[0077] - QoS Flow ID (QFI) marked in both DL and UL packets

[0078] According to an embodiment, the functions of the Uu-RRC 211 and 231 may include at least some of the following functions.

[0079] - Broadcast system information related to AS and NAS

[0080] - Paging initiated by 5GC or NG-RAN

[0081] - Establish and manage the RRC connection between the UE and NG-RAN, and add, modify and release carrier aggregation and dual connectivity between NRs or between NR and LTE (Establish, maintain and release the RRC connection between the UE and NG-RAN, including: add, modify and release carrier aggregation; add, modify and release dual connectivity in NR or between E-UTRA and NR.)

[0082] - Security features, including key management

[0083] - Establish, configure, maintain and release Signalling Radio Bearers (SRBs) and Data Radio Bearers (DRBs)

[0084] - UE mobility support (mobility functions include: handover and context transfer; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility.)

[0085] - QoS management function

[0086] - UE measurement reporting and reporting control

[0087] - Radio link failure detection and recovery (detection and recovery of radio link failure)

[0088] - NAS message transmission (NAS message transmission from UE to NAS / from NAS to UE)

[0089] Additionally, some of the following functions may be included to support the functionality of the side link.

[0090] - Configure sidelink resource allocation via system information or dedicated signaling

[0091] - Report UE side link information

[0092] - Sidelink related measurement configuration and reporting

[0093] - Sidelink traffic pattern reporting via UE assistance information (reporting UE assistance information for SL traffic pattern)

[0094] The main functions of Uu-PDCP 212 and 232 may include some of the following functions.

[0095] - Data transmission (user plane or control plane)

[0096] - Maintenance of PDCP Sequence Number (SN)

[0097] - Header compression and decompression using the Robust Header Compression (ROHC) protocol

[0098] - Header compression and decompression using the EHC protocol

[0099] - Compression and decompression of uplink PDCP service data units (SDUs): DEFLATE-based UDC only

[0100] - Encryption and decryption

[0101] - Integrity protection and integrity verification

[0102] - Timer-based SDU discard

[0103] - Routing for separate bearer

[0104] - copy

[0105] - Reordering and sequential delivery

[0106] - Out-of-order delivery

[0107] - Duplicate discard

[0108] According to an embodiment, the functions of the PC5-SRAP 213 , 221 and the Uu-SRAP 225 , 233 may include at least some of the following functions.

[0109] - Data transfer

[0110] - Determine the UE identifier and bearer identifier of the data packet (determine the UE ID field and bearer ID field of the data packet)

[0111] - Determine the egress link

[0112] - Determine the egress RLC channel

[0113] The main functions of the PC5 RLC 214, 222 and the Uu RLC 226, 234 may include some of the following functions.

[0114] - Transmission of upper layer protocol data units (PDUs)

[0115] - Sequence numbering (UM and AM) is independent of the sequence numbering in PDCP

[0116] - Error correction via Automatic Repeat Request (ARQ) (AM only)

[0117] - Segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs

[0118] - Reorganization of SDU (AM and UM)

[0119] - Duplicate detection (AM only)

[0120] - RLC SDU discard (AM and UM)

[0121] - RLC reconstruction

[0122] - Protocol error detection (AM only)

[0123] According to an embodiment, main functions of the PC5 MAC 215 , 223 and the Uu MAC 227 , 228 may include at least some of the following functions.

[0124] - Mapping between logical channels and transport channels

[0125] - Multiplexing MAC SDUs belonging to one or more logical channels (Multiplexing MAC SDUs from one or different logical channels onto a transport block (TB) for delivery to the physical layer on a transport channel)

[0126] - Demultiplexing of MAC SDUs belonging to one or more logical channels (demultiplexing MAC SDUs from transport blocks delivered from the physical layer on a transport channel to one or different logical channels)

[0127] - Dispatch information report

[0128] - Error correction via HARQ

[0129] - Logical channel prioritization

[0130] - Prioritization between overlapping resources of a UE

[0131] - Wireless resource selection

[0132] - Packet filtering

[0133] - Prioritization between uplink and sidelink transmissions for a given UE

[0134] - Sidelink CSI reporting

[0135] According to an embodiment, the PC5 PHY layer 216, 224 and the Uu PHY layer 228, 236 may encode and modulate the upper layer data to generate orthogonal frequency division multiplexing (OFDM) symbols, convert these symbols into RF band signals, and then transmit these signals through the antenna. In addition, the PC5 PHY layer 216, 224 and the Uu PHY layer 228, 236 may demodulate and decode the received OFDM symbols and send them to the upper layer.

[0136] According to an embodiment, transmission between the remote UE 210 and the relay UE 220 in the U2N relay may be performed through the PC5 relay RLC channel 240. Transmission between the relay UE 220 and the base station 230 may be performed through the Uu relay RLC channel 250.

[0137] According to an embodiment, for uplink data transmission via U2N relay, if the SRAP service data unit (SDU) received from the upper layer does not belong to SRB0, PC5-SRAP 213 of remote UE 210 can determine the UE ID corresponding to relay UE 220 received from base station 230. If the SRAP SDU received from the upper layer is an SRB, PC5-SRAP 213 of remote UE 210 can determine that the bearer ID is the same as the SRB ID. If the SRAP SDU received from the upper layer is a DRB, PC5-SRAP 213 of remote UE 210 can determine the bearer ID by using the value obtained by subtracting 1 from the DRB ID. PC5-SRAP 213 can generate an SRAP data protocol data unit (PDU) by combining the SRAP data SDU with the SRAP header containing UE ID and bearer ID information.

[0138] If the SRAP SDU received from the upper layer belongs to SRB0, PC5-SRAP 213 of the remote UE 210 can generate an SRAP data PDU identical to the SRAP data SDU, excluding the SRAP header. If the SRAP data PDU does not belong to SRB0, the SRAP data PDU can be transmitted on an egress PC5 relay RLC channel configured to transmit SRBs or DRBs received from the base station. In this case, one or more SRBs or one or more DRBs can be configured to be transmitted using a single PC5 relay RLC channel, or they can be configured to be transmitted using different PC5 relay RLC channels. If the SRB and DRB have the same bearer ID, the SRB and DRB can be distinguished and transmitted using different PC5 relay RLC channels. If the SRAP data PDU belongs to SRB0 or ​​SRB1, the SRAP data PDU can be transmitted on an egress PC5 relay RLC channel based on a specified configuration. The specified configuration can be shown in [Table 3-1] and [Table 3-2]. For example, the specified configuration may be as shown in [Table 3-1] and / or [Table 3-2].

[0139] [Table 3-1]

[0140] Parameters specified for NR sidelink L2 U2N relay operation, which uses a PC5 relay RLC channel for SRB0 message transmission / reception with remote UEs. The PC5 relay RLC channel using this configuration is named SL-RLC0.

[0141]

[0142] [Table 3-2]

[0143] Parameters of the PC5 relay RLC channel used for SRB1 RRC message transmission and reception to the remote UE. The PC5 relay RLC channel using this configuration is named SL-RLC1.

[0144]

[0145] According to an embodiment, PC5-SRAP 221 of relay UE 220 may deliver SRAP data PDUs received via the PC5 relay RLC channel to Uu-SRAP 225. If the received SRAP data PDUs were received via SL-RLC0, Uu-SRAP 225 of relay UE 220 may determine the UE ID corresponding to remote UE 210, received from base station 230. Uu-SRAP 225 of relay UE 220 may determine the bearer ID to be 0. Uu-SRAP 225 may generate an SRAP data protocol data unit (PDU) by combining the SRAP data SDUs with an SRAP header containing UE ID and bearer ID information. Uu-SRAP 225 of relay UE 220 may transmit the SRAP data PDUs on the egress Uu relay RLC channel configured for transmitting SRBs or DRBs, which channel is configured by base station 230. In this case, one or more SRBs or one or more DRBs can be configured to be sent using one Uu relay RLC channel, and can also be configured to be sent using different Uu relay RLC channels. If the SRB and DRB have the same bearer ID, the SRB and DRB can be distinguished and sent using different PC5 relay RLC channels.

[0146] According to an embodiment, for downlink transmission via U2N relay, the Uu-SRAP 225 of the relay UE 220 may deliver received SRAP data packets to the PC5-SRAP 221. The PC5-SRAP 221 of the relay UE 220 may determine the remote UE 210 corresponding to the UE ID included in the SRAP header, and the PC5-SRAP 221 in the relay UE 220 may transmit the SRAP data PDU on the egress PC5 relay RLC channel corresponding to the bearer ID configured by the base station 230 and configured for transmitting SRBs or DRBs. In this case, one or more SRBs or one or more DRBs may be configured to be transmitted using one Uu relay RLC channel, or may be configured to be transmitted using different Uu relay RLC channels. If the SRBs and DRBs have the same bearer ID, the SRBs and DRBs may be distinguished and transmitted using different Uu relay RLC channels.

[0147] According to an embodiment, if the SRAP Data PDU belongs to SRB0, PC5-SRAP 221 of relay UE 220 may remove the SRAP header from the SRAP Data PDU. If the SRAP Data PDU belongs to SRB0 or ​​SRB1, the SRAP Data PDU may be sent on the egress PC5 relay RLC channel based on a specified configuration, as shown in [Table 3-1] and / or [Table 3-2]. If the SRAP Data PDU received by PC5-SRAP 213 of remote UE 210 belongs to SRB0, the SRAP SDU may be delivered to Uu-RRC 211.

[0148] If the received SRAP data PDU does not belong to SRB0 and the radio bearer (RB) of the remote UE 210 is configured from the base station 230, the PC5-SRAP 213 of the remote UE 210 may remove the SRAP header and deliver the SRAP SDU to the Uu-PDCP 212 of the remote UE 210 corresponding to the bearer ID included in the SRAP header (for a DRB, a value obtained by incrementing the bearer ID by 1). If the received SRAP data PDU does not belong to SRB0 and the RB of the remote UE 210 is not configured from the base station 230, the PC5-SRAP 213 of the remote UE 210 may remove the SRAP header and deliver the SRAP SDU to the Uu-PDCP 212 corresponding to SRB1.

[0149] Figure 3 A flowchart illustrating a process in which a base station configures an adaptation layer of a UE-to-network (U2N) relay according to an embodiment of the present disclosure is shown.

[0150] refer to Figure 3 According to an embodiment, in operation 301, the remote UE 310 may establish a PC5 unicast link to communicate with the base station 330 via the relay UE 320. In this case, the establishment process may follow Figure 1 For example, a PC5 unicast link can be connected via Figure 1 Therefore, the present disclosure Figure 3 Examples and Figure 1 The embodiments can be combined.

[0151] According to an embodiment, in operation 303, the relay UE 320 may provide the base station with information for relay communication of the remote UE 310. The information that may be included in this case may be as shown in [Table 4].

[0152] [Table 4]

[0153] In operation 303, the base station 330 may transmit or deliver to the relay UE 320 a configuration for transmitting the SRB of the remote UE 310 based on the information provided by the relay UE 320. The information transmitted in this case may be as shown in [Table 5].

[0154] [Table 5]

[0155] In this case, the relay UE 320 can obtain a local ID corresponding to the layer 2 ID of the remote UE 310, and the obtained local ID can be used with Figure 2 The UE ID used in the embodiment is the same.

[0156] In operation 304, the relay UE 320 may transmit (RRCSetupRequest) the SRB0 message 302 transmitted by the remote UE 310 to the base station 330 through the Uu relay RLC channel configured in operation 303. The transmission method may be as follows: Figure 2 For example, according to Figure 2The method shown in FIG. 3 shows, the SRB0 message 302 sent by the remote UE 310 can be sent to the base station 330. Therefore, the present disclosure Figure 2 Examples and Figure 3 The embodiments can be combined.

[0157] According to the embodiment, in operation 305, the relay UE 320 may transmit (RRCSetup) the SRB0 message that has been received from the base station 330 to the remote UE 310 so as to be transmitted to the remote UE 310. The transmission method may be as follows: Figure 2 In this case, the information sent may be as shown in [Table 6].

[0158] [Table 6]

[0159] The remote UE 310 can obtain the local ID corresponding to the relay UE 320 for communication with the base station 330, and the obtained local ID can be used with Figure 2 The UE ID used in the embodiments is basically the same.

[0160] According to an embodiment, in operation 306, the remote UE 310 may transmit a message to the base station 330 and / or receive a message from the base station by using SRB1. During the message transmission and / or reception using SRB1, registration, authentication and / or security establishment may be performed via the core network and NAS, and capability information exchange and AS security establishment may be performed between the base station 330 and the remote UE 310. The transmission method may be as follows: Figure 2 as shown (RRC (e.g., RRCSetupComplete)).

[0161] According to an embodiment, in operation 307, the base station 330 may transmit and / or receive a message for establishing SRB2 and DRB to the remote UE 310. During the transmission and / or reception of the message for establishing SRB2 and DRB, the configuration of the PC5 relay RLC channel for transmitting SRB2 and DRB may also be transmitted. The transmission method may be as follows: Figure 2 As shown, the information to be sent can be as shown in [Table 6].

[0162] According to an embodiment, in operation 308, the base station 330 may transmit configuration (or configuration information) of the PC5 relay RLC channel and the Uu relay RLC channel to the relay UE 320 for transmitting SRB2 and DRB to the remote UE 310. The information to be transmitted may be as shown in [Table 5].

[0163] Although not shown in the figure, when the remote UE 310 or the relay UE 320 is to perform transmission using a PC5 relay RLC channel not based on a specified configuration, the Tx UE may configure the RLC channel via PC5-RRC signaling, and the information to be transmitted may be as shown in [Table 7].

[0164] [Table 7]

[0165] The RLC configuration information to be applied when the receiving UE receives the PC5 relay RLC channel may be determined by the receiving UE itself.

[0166] Figure 4 A wireless protocol structure of a UE-to-UE (U2U) relay according to an embodiment of the present disclosure is shown.

[0167] refer to Figure 4According to an embodiment, the source UE 410, the relay UE 420, and / or the target UE 430 may establish a direct connection via a sidelink interface. For example, the source UE 410 and the relay UE 420 may be configured to be directly connected via the sidelink interface, and the relay UE 420 and the target UE 430 may be configured to be directly connected via the sidelink interface. If the source UE 410 and the target UE 430 are within a range where sidelink communication is possible, the source UE 410 and the target UE 430 may be configured to be directly connected via the sidelink interface. The source UE 410 and the target UE 430 may be referred to as UEs capable of sending and / or receiving data and signaling to and from the target UE 430 via U2U relay. In the present disclosure, the source UE 410 may be referred to as a UE that sends a request to establish a PC5 unicast link or sends a request to establish a sidelink radio bearer (SLRB) during communication with the target UE 430. Source UE 410 may initiate PC5 unicast link establishment via relay UE 420 to transmit and / or receive data and signaling to and / or from target UE 430 via the U2U relay. If the sidelink reference signal received power (SL-RSRP) between source UE 410 and relay UE 420, or between relay UE 420 and target UE 430, decreases to a specific level or lower during the transmission and / or reception of data and signaling to and / or from target UE 430 via relay UE 420, or if an upper layer instructs reselection due to satisfaction of a relay UE reselection condition, source UE 410 may reselect or determine a third UE as a relay UE instead of connecting to the existing relay UE 420. Source UE 410 may initiate PC5 unicast link establishment via the third UE to provide services associated with target UE 430 via the U2U relay. For example, the upper layer may include a V2X layer and / or a prose layer.

[0168] According to an embodiment, the wireless protocol of the U2U relay may include PC5-SDAP or PC5-RRC 411 and 431, PC5-PDCP 412 and 432, PC5-SRAP 413 and 433, PC5-RLC 414 and 434, PC5-MAC 415 and 435, PC5-PHY 416 and 436 in the source UE 410 and the target UE 430, respectively, and may include PC5-SRAP 421 and 425, PC5-RLC 422 and 426, PC5-MAC 423 and 427, and PC5-PHY 424 and 428 in the relay UE 420.

[0169] According to an embodiment, the functions of the PC5-SDAPs 411 and 431 may include at least some of the following functions.

[0170] - Mapping between QoS flows and sidelink data radio bearers

[0171] The main functions of PC5-RRC 411 and 431 may include some of the following functions.

[0172] - PC5-RRC message transmission between peer UEs

[0173] - Maintenance and release of PC5-RRC connection between two UEs

[0174] - Detect sidelink radio link failure of PC5-RRC connection

[0175] The main functions of PC5-PDCP 412 and 432 may include some of the following functions.

[0176] - Data transmission (user plane or control plane)

[0177] - Maintenance of PDCP Sequence Number (SN)

[0178] - Header compression and decompression using the ROHC protocol

[0179] - Header compression and decompression using the EHC protocol

[0180] - Compression and decompression of uplink PDCP SDU: only deflate-based UDC

[0181] - Encryption and decryption

[0182] - Integrity protection and integrity verification

[0183] - Timer-based SDU discard

[0184] - Routing for separate bearer

[0185] - Reordering and sequential delivery

[0186] - Out-of-order delivery for unicast transmission only

[0187] The main functions of PC5-SRAPs 413, 421, 425, and 433 may include some of the following functions.

[0188] - Data transfer

[0189] - Determine the UE identifier and bearer identifier of the data packet (determine the UE ID field and bearer ID field of the data packet)

[0190] - Determine the egress link

[0191] - Determine the egress RLC channel

[0192] According to an embodiment, the functions of the PC5-RLCs 414 , 422 , 426 , and 434 may include at least some of the following functions.

[0193] - Transmission of upper layer PDU

[0194] - Sequence numbering (UM and AM) is independent of the sequence numbering in PDCP

[0195] - Error correction via ARQ (AM only)

[0196] - Segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs

[0197] - Reorganization of SDU (AM and UM)

[0198] - Duplicate detection (AM only)

[0199] - RLC SDU discard (AM and UM)

[0200] - RLC reconstruction

[0201] - Protocol error detection (AM only)

[0202] According to an embodiment, the functions of PC5-MAC 415 , 423 , 427 , and 435 may include at least some of the following functions.

[0203] - Mapping between logical channels and transport channels

[0204] - Multiplexing MAC SDUs belonging to one or more logical channels (Multiplexing MAC SDUs from one or different logical channels onto a transport block (TB) for delivery to the physical layer on a transport channel)

[0205] - Demultiplexing of MAC SDUs belonging to one or more logical channels (demultiplexing MAC SDUs from transport blocks delivered from the physical layer on a transport channel to one or different logical channels)

[0206] - Dispatch information report

[0207] - Error correction via HARQ

[0208] - Logical channel prioritization

[0209] - Prioritization between overlapping resources of a UE

[0210] - Radio resource selection

[0211] - Packet filtering

[0212] - Prioritization between uplink and sidelink transmissions for a given UE

[0213] - Sidelink CSI reporting

[0214] According to an embodiment, the PC5-PHY layers 416, 424, 428, and 436 may encode and modulate the upper layer data to generate OFDM symbols, convert these symbols into radio frequency (RF) band signals, and then transmit these signals through an antenna. In addition, the received OFDM symbols may be demodulated and decoded and passed to the upper layer.

[0215] In U2U relay, transmission between the source UE 410 and the relay UE 420 may be performed through a PC5 relay RLC channel 440 , and transmission between the relay UE 420 and the target UE 430 may be performed through a PC5 relay RLC channel 450 .

[0216] Figure 5 A flowchart of a process for establishing a PC5 unicast link for UE-to-UE (U2U) relay according to an embodiment of the present disclosure is shown.

[0217] refer to Figure 5 According to an embodiment, in operation 501 , the source UE 510 may transmit a direct communication request message to the relay UE 520 to communicate with the target UE 530 via the relay UE 520 .

[0218] According to an embodiment, when the relay UE 520 receives the direct communication request message in operation 501 , the relay UE 520 may perform PC5 security configuration such as mutual authentication and encryption key configuration for the PC5 unicast link to the source UE 510 in operation 502 .

[0219] According to an embodiment, if it is determined that mutual authentication, encryption key configuration, etc. for direct connection establishment between the relay UE 520 and the source UE 510 have been performed normally, in operation 503, the relay UE 520 may send a direct communication request message to the target UE 530.

[0220] According to an embodiment, upon receiving the direct communication request message in operation 503 , the target UE 530 may perform PC5 security configuration, such as mutual authentication and encryption key configuration, for the PC5 unicast link to the relay UE 520 in operation 504 .

[0221] According to an embodiment, if it is determined that mutual authentication, encryption key configuration, etc. for establishing a direct connection between the target UE 530 and the relay UE 520 have been performed normally, then in operation 505, the target UE 530 can send a direct communication acceptance message to the relay UE 520, and the PC5 unicast link establishment between the relay UE 520 and the target UE 530 can be completed.

[0222] According to an embodiment, when the relay UE 520 receives a direct communication acceptance message from the target UE 530 in operation 505, in operation 506, the relay UE 520 may send direct communication acceptance information to the source UE 510 to complete the establishment of the PC5 unicast link to the source UE 510, and complete the establishment of the PC5 unicast link between the source UE 510 and the relay UE 520.

[0223] According to an embodiment, in order to establish an end-to-end PC5 unicast link to the target UE 530, the source UE 510 may initiate or perform a PC5 unicast link establishment via the relay UE 520 in operation 507. The end-to-end PC5 unicast link establishment may include a direct communication request, a PC5 security configuration, and / or a direct communication acceptance sent between the source UE 510 and the target UE 530.

[0224] Figure 6 A flowchart of a process for acquiring a local identifier (local identity) of a UE-to-UE (U2U) relay from a base station according to an embodiment of the present disclosure is shown.

[0225] refer to Figure 6 , the source UE 610 according to the embodiment may need to obtain the UE ID corresponding to the target UE included in the SRAP header in order to send an end-to-end message about the target UE. Figure 6 The source UE 610 may correspond to Figure 5 source UE 510, and unless otherwise inconsistent, Figure 5 The description of the source UE 510 may also be applied to Figure 6 The source UE 610.

[0226] According to an embodiment, when the source UE 610 is in the RRC_IDLE state or the RRC_INACTIVE state, in which an RRC connection to the base station 630 has not yet been established, a process for establishing an RRC connection may be initiated. If the source UE 610 is in the RRC_CONNECTED state, in which an RRC connection to the base station 630 has already been established, then in operation 601, the source UE 610 may provide the base station 630 with information for performing U2U relay communication with the target UE. The information that may be included in the information for performing U2U relay communication with the target UE may be as shown in [Table 4], and the information that may be additionally transmitted may include some of the examples in [Table 8]. For example, the information for performing U2U relay communication with the target UE may include at least one of the information elements included in [Table 4]. For example, the information for performing U2U relay communication with the target UE may include at least one of the information elements included in [Table 4].

[0227] [Table 8]

[0228] According to an embodiment, in order to provide information for U2U relay to the relay UE 620, the source UE 610 may provide, deliver, or transmit information for U2U relay communication with the target UE to the relay UE 620 in operation 602. The information that may be included in the information provided to the relay UE 620 may include at least some of the examples in [Table 8].

[0229] Depending on the embodiment, relay UE 620 may need to obtain the UE ID of source UE 610 and / or the UE ID corresponding to the target UE, which is included in the SRAP header, in order to transmit an end-to-end message between source UE 610 and the target UE. If, in operation 602, relay UE 620 has already received a message transmitted by source UE 610, or a PC5 unicast link has been established between source UE 610 and relay UE 620, and a PC5 unicast link has been established between relay UE 620 and the target UE, and then determines that it is necessary to obtain the UE IDs corresponding to source UE 610 and the target UE, then, in operation 603, relay UE 620 may provide information for U2U relay communication between source UE 610 and the target UE to base station 630. The information provided to base station 630 for U2U relay communication may include information as shown in Table 4, and additional information that may be transmitted may include some of the examples in Table 8.

[0230] According to an embodiment, when the base station 630 receives information for U2U relay communication between the source UE 610 and the target UE from the source UE 610 or the relay UE 620 in operation 601 or operation 603, the base station 630 may provide SRAP configuration information for U2U relay communication to the source UE 610 or the relay UE 620 in operation 604 or operation 605. For example, in operation 604, the base station 630 may provide the SRAP configuration information for U2U relay communication to the relay UE 620. For example, in operation 605, the base station 630 may provide the SRAP configuration information for U2U relay communication to the source UE 610. Information that may be included in the SRAP configuration information may include at least some of the examples in [Table 9].

[0231] [Table 9]

[0232] If the relay UE 620 has received the local ID used in the U2U relay from the base station 630 in operation 603 or has determined the local ID used in the U2U relay, the relay UE 620 may provide or transmit the local ID information to the source UE 610 in operation 606. Information provided to the source UE 610 (e.g., local ID information) may include at least some of the examples in Table 9.

[0233] Figure 7 A flow chart is shown for configuring an adaptation layer for an end-to-end (E2E) sidelink signaling radio bearer (SL-SRB) relay for a UE-to-UE (U2U) relay using a specific configuration according to an embodiment of the present disclosure.

[0234] refer to Figure 7 According to an embodiment, the source UE 710 and the relay UE 720 may have established a PC5 unicast link, and the relay UE 720 and the target UE 730 may have established a PC5 unicast link. The establishment of each PC5 unicast link may follow Figure 5 Examples of this disclosure. Figure 7 The source UE 710 may correspond to Figure 5 source UE 510, and unless otherwise inconsistent, Figure 5 The description of the source UE 510 may also be applied to Figure 7 The source UE 710. Figure 5 The description of the establishment of the PC5 unicast link described in operations 501 to 502 can also be applied to Figure 7 .

[0235] According to an embodiment, in order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 701, the source UE 710 may transmit PC5-RRC signaling to the relay UE 720 and configure SRAP.

[0236] Condition 1: When the upper layer requests the transmission of at least one end-to-end SL-SRB message to the target UE 730

[0237] Condition 2: When at least one PC5 relay RLC channel or SRAP has not been configured for transmission to the target UE 730

[0238] Condition 3: When a PC5 unicast link has been established between the source UE 710 and the relay UE 720

[0239] Condition 4: When the upper layer has instructed to initiate U2U relay with the target UE 730

[0240] Information that may be included in the information transmitted during PC5-RRC signaling may be at least some of the examples in [Table 10].

[0241] [Table 10]

[0242] According to an embodiment, when the relay UE 720 receives the SRAP configuration from the source UE 710 in operation 701, if it is determined that the configuration has been normally applied, then in operation 702, the relay UE 720 may send information indicating that the application of the configuration has been completed to the source UE 710 via PC5-RRC signaling. For example, when the source UE 710 sends the SRAP configuration in operation 701 and / or receives the SRAP configuration application completion in operation 702, the source UE 710 may determine or recognize that the SRAP configuration for end-to-end SL-SRB transmission to the target UE 730 has been completed. For example, when the relay UE 720 receives the SRAP configuration in operation 701 and / or sends the SRAP configuration application completion in operation 702, the relay UE 720 may determine or recognize that the SRAP configuration between the source UE 710 and the relay UE 720 has been completed.

[0243] In order to receive and transmit end-to-end SL-SRB messages, if at least one of the following conditions is satisfied, in operation 703 , the relay UE 720 may transmit PC5-RRC signaling to the source UE 710 and configure SRAP.

[0244] Condition 1: When at least one PC5 relay radio link control (RLC) channel or SRAP for transmission from the source UE 710 to the target UE 730 has not been configured

[0245] Condition 2: When a PC5 unicast link has been established between the source UE 710 and the relay UE 720

[0246] Condition 3: When the upper layer has instructed to initiate U2U relay between the source UE 710 and the target UE 730

[0247] Information that may be included in the information transmitted during PC5-RRC signaling transmission may be at least some of the examples in [Table 10].

[0248] According to an embodiment, when the source UE 710 receives the SRAP configuration from the relay UE 720 in operation 703, if it is determined that the configuration has been normally applied, then in operation 704, the source UE 710 may send information indicating that the application of the configuration has been completed to the relay UE 720 via PC5-RRC signaling. For example, when the source UE 710 receives the SRAP configuration in operation 703 and / or sends the SRAP configuration application completion in operation 704, the source UE 710 may determine or recognize that the SRAP configuration for end-to-end SL-SRB transmission has been completed. For example, when the relay UE 720 sends the SRAP configuration in operation 703 and / or receives the SRAP configuration application completion in operation 704, the relay UE 720 may determine or recognize that the SRAP configuration between the source UE 710 and the relay UE 720 has been completed.

[0249] According to an embodiment, in order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 705 , the relay UE 720 may transmit PC5-RRC signaling to the target UE 730 and configure SRAP.

[0250] Condition 1: When at least one PC5 relay RLC channel or SRAP for transmission from the source UE 710 to the target UE 730 has not been configured

[0251] Condition 2: When a PC5 unicast link has been established between the source UE 710 and the relay UE 720

[0252] Condition 3: When a PC5 unicast link has been established between the relay UE 720 and the target UE 730

[0253] Condition 4: When the source UE 710 has configured SRAP via PC5-RRC signaling in operation 701

[0254] Condition 5: When the SRAP configuration between the source UE 710 and the relay UE 720 has been completed

[0255] Condition 6: When the upper layer has instructed to initiate U2U relay between the source UE 710 and the target UE 730

[0256] The information that may be included in the information transmitted via PC5-RRC signaling may be at least some of the examples in [Table 11].

[0257] [Table 11]

[0258] According to an embodiment, when the target UE 730 receives the SRAP configuration from the relay UE 720 in operation 705, if it is determined that the configuration has been normally applied, the target UE 730 may transmit information indicating that the application of the configuration has been completed to the relay UE 720 via PC5-RRC signaling in operation 706. For example, when the target UE 730 receives the SRAP configuration in operation 705 and / or transmits "SRAP configuration application complete" in operation 706, the target UE 730 may determine that the SRAP configuration for end-to-end SL-SRB transmission has been completed. For example, when the relay UE 720 transmits the SRAP configuration in operation 705 and / or receives "SRAP configuration application complete" in operation 706, the relay UE 720 may determine that the SRAP configuration between the target UE 730 and the relay UE 720 has been completed.

[0259] According to an embodiment, in operation 707, the source UE 710 may initiate or perform establishment of an end-to-end PC5 unicast link to the target UE 730. The SL-SRBs used to transmit signaling for exchanging end-to-end PC5-S and PC5-RRC messages may include SL-SRB0, SL-SRB1, SL-SRB2, and / or SL-SRB3, and configuration information about SL-SRB0, configuration information about SL-SRB1, configuration information about SL-SRB2, and / or configuration information about SL-SRB3 may be stored in each of the UEs 710, 720, and 730 as a designated configuration.

[0260] According to an embodiment, the designated configuration information of the SL-SRB may be as shown in [Table 1-1], [Table 1-2], [Table 1-3], and / or [Table 1-4]. As another example, to distinguish between a non-relay target SL-SRB and a U2U relay target SL-SSB, the designated configuration information of the SL-SRB may be stored in different designated configurations by changing some of the designated configurations in [Table 1-1], [Table 1-2], [Table 1-3], and / or [Table 1-4]. For example, the non-relay target SL-SRB may store first configuration information (e.g., the designated configurations in [Table 1-1], [Table 1-2], [Table 1-3], and / or [Table 1-4]), while the U2U relay target SL-SRB may store second configuration information different from the first configuration information. As an embodiment, one or more SL-SRB designated configurations for transmitting a combination including at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 requiring U2U relay may have different values ​​from those in [Table 1-1], [Table 1-2], [Table 1-3], and / or [Table 1-4]. logicalChannelIdentity The value of .

[0261] To distinguish between the PC5 RLC channel through which non-relay target SL-SRBs are transmitted and the PC5 RLC channel through which U2U relay target SL-SRBs are transmitted, the PC5 relay RLC channel stored as a designated configuration in the respective UEs 710, 720, and 730 may be used. The designated configuration information for the SL-RLC may be as shown in [Table 3-1] and / or [Table 3-2], and at least some of the designated configurations in [Table 3-1] and / or [Table 3-2] may be modified and stored as different designated configurations. For example, the PC5 RLC channel through which non-relay target SL-SRBs are transmitted may be stored in each UE 710, 720, or 730 in a first configuration (e.g., the designated configurations in [Table 3-1] and / or [Table 3-2]), and the PC5 RLC channel through which U2U relay target SL-SRBs are transmitted may be stored in each UE 710, 720, or 730 in a second configuration different from the first configuration.

[0262] As an embodiment, one or more SL-RLC designated configurations for transmitting a combination including at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 that is U2U relayed may have different values ​​from those in [Table 3-1] and / or [Table 3-2]. logicalChannelIdentity The value of .

[0263] According to an embodiment, the SRAP transmission portion of the source UE 710 may determine or identify the UE identity or identification (ID) corresponding to the target UE 730 in order to transmit the SRAP SDU received from the upper layer to the target UE 730. The UE ID may be substantially the same as the local ID configured in the SRAP of the source UE 710 in operation 701 and / or operation 703. The SRAP of the source UE 710 may determine or identify the bearer ID based on the SL-SRB identifier received from the upper layer. The SRAP transmission portion of the source UE 710 may generate an SRAP data PDU by combining or assembling the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The source UE 710 may transmit the generated SRAP data PDU to the relay UE 720 via a PC5 relay RLC channel indicated by a designated configuration configured for transmitting the SRAP data PDU via the SL-SRB.

[0264] According to an embodiment, when relay UE 720 receives an SRAP Data PDU transmitted by source UE 710, the SRAP receiving section of relay UE 720 may deliver the SRAP Data PDU received from the lower layer to the SRAP transmitting section for transmission to target UE 730. The SRAP transmitting section of relay UE 720 may determine or identify target UE 730 corresponding to the UE ID in the SRAP header. The UE ID may be the same as the local ID configured in the SRAP of relay UE 720 in operations 701, 703, and 705. If the UE ID is not configured in the SRAP, relay UE 720 may discard or remove the SRAP Data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 720 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP Data PDU was received. The relay UE 720 may perform transmission to the target UE 730 through the PC5 relay RLC channel indicated by the designated configuration configured to transmit the SL-SRB corresponding to the bearer ID of the SRAP header.

[0265] According to an embodiment, when the target UE 730 receives the SRAP data PDU transmitted by the relay UE 720, if the UE ID included in the header of the SRAP data PDU received from the lower layer is different from the local ID configured in operation 705, the SRAP reception section of the target UE 730 may discard the SRAP data PDU. The SRAP reception section of the target UE 730 may remove the header of the SRAP data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the SL-SRB corresponding to the bearer ID included in the header of the SRAP data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, the target UE 730 may distinguish between the SL-DRB and the SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU has been received.

[0266] According to an embodiment, the SRAP transmission portion of the target UE 730 may determine or identify the UE ID corresponding to the source UE 710 in order to transmit the SRAP SDU received from the upper layer to the source UE 710. The UE ID may be substantially the same as the local ID configured in the SRAP of the target UE 730 in operation 705. The SRAP of the target UE 730 may determine the bearer ID based on the SL-SRB identifier received from the upper layer. The SRAP transmission portion of the target UE 730 may generate an SRAP data PDU by combining the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The target UE 730 may transmit the generated SRAP data PDU to the relay UE 720 via the PC5 relay RLC channel indicated by the specified configuration configured for transmitting the SRAP data PDU via the SL-SRB.

[0267] According to an embodiment, when relay UE 720 receives an SRAP data PDU transmitted by target UE 730, the SRAP receiving section of relay UE 720 may deliver the SRAP data PDU received from the lower layer to the SRAP transmitting section for transmission to source UE 710. The SRAP transmitting section of relay UE 720 may determine the source UE 710 corresponding to the UE ID in the SRAP header. The UE ID may be substantially the same as the local ID configured in the SRAP of relay UE 720 in operations 701, 703, and / or 705. If the UE ID is not configured in the SRAP, relay UE 720 may discard the SRAP data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 720 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU was received. The relay UE 720 may perform transmission to the source UE 710 through the PC5 relay RLC channel indicated by the designated configuration configured to transmit the SL-SRB corresponding to the bearer ID of the SRAP header.

[0268] According to an embodiment, when source UE 710 receives an SRAP data PDU transmitted by relay UE 720, if the UE ID included in the header of the SRAP data PDU received from the lower layer is different from the local ID configured in operation 701 and / or operation 703, the SRAP reception portion of source UE 710 may discard the SRAP data PDU. The SRAP reception portion of source UE 710 may remove the header of the SRAP data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the SL-SRB corresponding to the bearer ID included in the header of the SRAP data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, source UE 710 may distinguish between an SL-DRB and an SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU was received.

[0269] Figure 8 A flow chart is shown for configuring an adaptation layer for an end-to-end (E2E) sidelink signaling radio bearer (SL-SRB) relay for a UE-to-UE (U2U) relay using a specific configuration according to an embodiment of the present disclosure.

[0270] refer to Figure 8 According to an embodiment, the source UE 810 and the relay UE 820 may have established a PC5 unicast link, and the relay UE 820 may establish a PC5 unicast link to the target UE 830. The establishment of each PC5 unicast link may follow Figure 5 .

[0271] In order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 801 , the source UE 810 may transmit PC5-RRC signaling to the relay UE 820 and configure SRAP.

[0272] Condition 1: When the upper layer requests the transmission of at least one end-to-end SL-SRB message to the target UE 830

[0273] Condition 2: When a PC5 relay RLC channel for sending at least one end-to-end SL-SRB message to be sent to the target UE 830 has not been configured

[0274] Condition 3: When at least one PC5 relay RLC channel or SRAP has not been configured for transmission to the target UE 830

[0275] Condition 4: When a PC5 unicast link has been established between the source UE 810 and the relay UE 820

[0276] Condition 5: When the upper layer has instructed to initiate U2U relay with the target UE 830

[0277] The information that can be included in the information sent when PC5-RRC signaling is sent to the relay UE 820 can be at least some of the examples in [Table 11a]. Additionally, information for configuration between the relay UE 820 and the target UE 830 can also be included, and this information can be as in the example in [Table 11a].

[0278] [Table 11a]

[0279] According to an embodiment, the SL-SRB used to transmit signaling for exchanging end-to-end PC5-S and PC5-RRC messages may correspond to SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3. The RLC channel used for SL-SRB relay transmission may be determined based on PC5 relay RLC channel configuration information between source UE 810 and relay UE 820, which configuration information is transmitted in operation 801. As an embodiment, when an SL-SRB ID is indicated in operation 801, each SL-SRB may be transmitted via the indicated PC5 relay RLC channel. In this case, the PC5 relay RLC channel through which at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 is transmitted may be configured. As an embodiment, when the SL-SRB indicator is included in the PC5 relay RLC channel configuration information transmitted in operation 801, SL-SRB0, SL-SRB1, SL-SRB2 and / or SL-SRB3 may be transmitted through a single PC5 relay RLC channel.

[0280] According to an embodiment, when the relay UE 820 receives the SRAP configuration from the source UE 810 in operation 801, if it is determined that the SRAP configuration has been normally applied, then in operation 802, the relay UE 820 may send information indicating that the application of the configuration has been completed to the source UE 810 via PC5-RRC signaling. For example, when the source UE 810 sends the SRAP configuration in operation 801 or receives the SRAP configuration application completion in operation 802, the source UE 810 may determine or recognize that the SRAP configuration for end-to-end SL-SRB transmission to the target UE 830 has been completed. For example, when the relay UE 820 receives the SRAP configuration in operation 801 or sends the SRAP configuration application completion in operation 802, the relay UE 820 may determine or recognize that the SRAP configuration between the source UE 810 and the relay UE 820 has been completed.

[0281] According to an embodiment, in order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 803 , the relay UE 820 may transmit PC5-RRC signaling to the target UE 830 and configure SRAP.

[0282] Condition 1: When at least one PC5 relay RLC channel or SRAP for transmission from the source UE 810 to the target UE 830 has not been configured

[0283] Condition 2: When a PC5 unicast link has been established between the source UE 810 and the relay UE 820

[0284] Condition 3: When a PC5 unicast link has been established between the relay UE 820 and the target UE 830

[0285] Condition 4: When the source UE 810 has configured SRAP via PC5-RRC signaling in operation 801

[0286] Condition 5: When the SRAP configuration between the source UE 810 and the relay UE 820 has been completed

[0287] Condition 6: When the upper layer has instructed to initiate U2U relay between the source UE 810 and the target UE 830

[0288] In this case, the information that may be included in the SRAP configuration information may be some of the examples in [Table 12]. For example, the SRAP configuration may include at least one of the information elements in [Table 12].

[0289] [Table 12]

[0290] The SL-SRB used to transmit signaling for exchanging end-to-end PC5-S and PC5-RRC messages may correspond to SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3. The RLC channel used for SL-SRB relay transmission may be determined based on PC5 relay RLC channel configuration information between relay UE 820 and target UE 830, which is transmitted in operation 803. As an example, in operation 803, relay UE 820 may transmit the U2U relay configuration to target UE 830 via PC5-RRC signaling.

[0291] If the source UE 810 delivers the SL-SRB ID, indicator, and / or PC5 relay RLC channel configuration information between the relay UE 820 and the target UE 830 to the relay UE 820 in operation 801, the U2U relay configuration transmitted in operation 803 may be configured to be the same as at least one of the SL-SRB ID, indicator, or PC5 relay RLC channel configuration information between the relay UE 820 and the target UE 830 transmitted in operation 801. The PC5 relay RLC channel ID for transmitting the SL-SRB may be selected by the relay UE 820.

[0292] As an example, when the SL-SRB ID is indicated in operation 803, each SL-SRB may be transmitted via the indicated PC5 relay RLC channel. In this case, a PC5 relay RLC channel may be configured through which at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 is transmitted. As an example, when the SL-SRB indicator is included in the U2U relay configuration in operation 803, SL-SRB0, SL-SRB1, SL-SRB2, and / or SL-SRB3 may be transmitted via a single PC5 relay RLC channel.

[0293] According to an embodiment, when the target UE 830 receives the SRAP configuration from the relay UE 820 in operation 803, if it is determined that the configuration has been normally applied, the target UE 830 may transmit information indicating that the application of the configuration has been completed to the relay UE 820 via PC5-RRC signaling in operation 804. For example, when the target UE 830 receives the SRAP configuration in operation 803 or transmits "SRAP configuration application complete" in operation 804, the target UE 830 may determine that the SRAP configuration for end-to-end SL-SRB transmission has been completed. For example, when the relay UE 820 transmits the SRAP configuration in operation 803 or receives "SRAP configuration application complete" in operation 804, the relay UE 820 may determine that the SRAP configuration between the target UE 830 and the relay UE 720 has been completed.

[0294] According to an embodiment, in order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 805 , the target UE 830 may transmit PC5-RRC signaling to the relay UE 820 and configure SRAP.

[0295] Condition 1: When the upper layer requests the transmission of at least one end-to-end SL-SRB message to the source UE 810

[0296] Condition 2: When a PC5 relay RLC channel for sending at least one end-to-end SL-SRB message to be sent to the source UE 810 has not been configured

[0297] Condition 3: When at least one PC5 relay RLC channel or SRAP has not been configured for transmission to the source UE 810

[0298] Condition 4: When a PC5 unicast link has been established between the target UE 830 and the relay UE 820

[0299] Condition 5: When the upper layer has instructed to initiate U2U relay with the source UE 810

[0300] The information that may be included in the information transmitted via PC5-RRC signaling in operation 805 may be at least some of the information in the examples in Table 13. Alternatively, information for configuration between relay UE 820 and source UE 810 may be included, and this information may be as in the examples in Table 13. For example, the information transmitted via PC5-RRC signaling may include at least one of the information elements in Table 13. For example, the information for configuration between relay UE 820 and source UE 810 may include at least one of the information elements in Table 13.

[0301] [Table 13]

[0302] According to an embodiment, the SL-SRB used to transmit signaling for exchanging end-to-end PC5-S and PC5-RRC messages may correspond to SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3. The RLC channel used for SL-SRB relay transmission may be determined based on PC5 relay RLC channel configuration information between target UE 830 and relay UE 820, which is transmitted in operation 805. As an example, when an SL-SRB ID is indicated in operation 805, each SL-SRB may be transmitted via the indicated PC5 relay RLC channel. In this case, the PC5 relay RLC channel through which at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 is transmitted may be configured. As an embodiment, when the SL-SRB indicator is included in the U2U relay configuration in operation 805 , SL-SRB0 , SL-SRB1 , SL-SRB2 , and / or SL-SRB3 may be transmitted through a single PC5 relay RLC channel.

[0303] According to an embodiment, when the relay UE 820 receives the SRAP configuration from the target UE 830 in operation 805, if it is determined that the configuration has been normally applied, then in operation 806, the relay UE 820 may send information indicating that the application of the configuration has been completed to the target UE 830 via PC5-RRC signaling. For example, when the target UE 830 sends the SRAP configuration in operation 805 or receives the SRAP configuration application completion in operation 806, the target UE 830 may determine that the SRAP configuration for end-to-end SL-SRB transmission to the source UE 810 has been completed. For example, when the relay UE 820 receives the SRAP configuration in operation 805 or sends the SRAP configuration application completion in operation 806, the relay UE 820 may determine that the SRAP configuration between the target UE 830 and the relay UE 820 has been completed.

[0304] According to an embodiment, in order to receive and transmit an end-to-end SL-SRB message, if at least one of the following conditions is satisfied, in operation 807 , the relay UE 820 may transmit PC5-RRC signaling to the source UE 810 and configure SRAP.

[0305] Condition 1: When at least one PC5 relay RLC channel or SRAP for transmission from the target UE 830 to the source UE 810 has not been configured

[0306] Condition 2: When a PC5 unicast link has been established between the source UE 810 and the relay UE 820

[0307] Condition 3: When a PC5 unicast link has been established between the relay UE 820 and the target UE 830

[0308] Condition 4: When the target UE 830 has configured SRAP via PC5-RRC signaling in operation 805

[0309] Condition 5: When the SRAP configuration between the target UE 830 and the relay UE 820 has been completed

[0310] Condition 6: When the upper layer has instructed to initiate U2U relay between the source UE 810 and the target UE 830

[0311] The information that may be included in the SRAP configuration may include at least some of the examples in [Table 14]. For example, the information included in the SRAP configuration may include at least one of the information elements in [Table 14].

[0312] [Table 14]

[0313] According to an embodiment, the SL-SRB used to transmit signaling for exchanging end-to-end PC5-S and PC5-RRC messages may correspond to SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3. The RLC channel used for SL-SRB relay transmission may be determined or identified based on PC5 relay RLC channel configuration information between relay UE 820 and source UE 810, which is transmitted in operation 807. As an embodiment, in operation 807, relay UE 820 may transmit the U2U relay configuration to source UE 810 during PC5-RRC signaling of relay UE 820.

[0314] If the target UE 830 delivers the SL-SRB ID, indicator, and / or PC5 relay RLC channel configuration information between the relay UE 820 and the source UE 810 in operation 805, the U2U relay configuration transmitted in operation 807 may be configured to be the same as at least one of the SL-SRB ID, indicator, or PC5 relay RLC channel configuration information between the relay UE 820 and the source UE 810 transmitted in operation 805. The PC5 relay RLC channel ID for transmitting the SL-SRB may be selected by the relay UE 820.

[0315] As an example, when the SL-SRB ID is indicated in operation 807, each SL-SRB may be transmitted through the indicated PC5 relay RLC channel. In this case, a PC5 relay RLC channel may be configured through which at least one of SL-SRB0, SL-SRB1, SL-SRB2, or SL-SRB3 is transmitted. As an example, in operation 807, when the SL-SRB indicator is included, SL-SRB0, SL-SRB1, SL-SRB2, and / or SL-SRB3 may be transmitted through a single PC5 relay RLC channel.

[0316] According to an embodiment, when the source UE 810 receives the SRAP configuration from the relay UE 820 in operation 807, if it is determined that the configuration has been normally applied, the source UE 810 may transmit information indicating that the application of the configuration has been completed to the relay UE 820 via PC5-RRC signaling in operation 808. For example, when the source UE 810 receives the SRAP configuration in operation 807 or transmits the SRAP configuration application completion in operation 808, the source UE 810 may determine that the SRAP configuration for end-to-end SL-SRB transmission has been completed. For example, when the relay UE 820 transmits the SRAP configuration in operation 807 or receives the SRAP configuration application completion in operation 808, the relay UE 820 may determine that the SRAP configuration between the source UE 810 and the relay UE 720 has been completed.

[0317] According to an embodiment, in operation 809 , the source UE 810 may initiate establishment of an end-to-end PC5 unicast link to the target UE 830 .

[0318] According to an embodiment, the SRAP transmission portion of the source UE 810 may determine the UE ID corresponding to the target UE 830 in order to transmit the SRAP SDU received from the upper layer to the target UE 830. The UE ID may be substantially the same as the local ID configured in the SRAP of the source UE 810 in operation 801 and / or operation 807. The SRAP of the source UE 810 may determine the bearer ID based on the SL-SRB identifier received from the upper layer. The SRAP transmission portion of the source UE 810 may generate an SRAP data PDU by combining the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The source UE 810 may transmit the generated SRAP data PDU to the relay UE 820 via a PC5 relay RLC channel configured to transmit the SRAP data PDU via the SL-SRB.

[0319] According to an embodiment, when relay UE 820 receives an SRAP Data PDU transmitted by source UE 810, the SRAP receiving section of relay UE 820 may deliver the SRAP Data PDU received from the lower layer to the SRAP transmitting section for transmission to target UE 830. The SRAP transmitting section of relay UE 820 may determine the target UE 830 corresponding to the UE ID in the SRAP header. The UE ID may be substantially the same as the local ID configured in the SRAP of relay UE 820 in operations 801, 803, 805, and / or 807. If the UE ID is not configured in the SRAP, relay UE 820 may discard the SRAP Data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 820 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP Data PDU was received. The relay UE 820 may perform transmission to the target UE 830 through a PC5 relay RLC channel configured to transmit the SL-SRB corresponding to the bearer ID of the SRAP header.

[0320] According to an embodiment, when the target UE 830 receives the SRAP Data PDU transmitted by the relay UE 820, if the UE ID included in the header of the SRAP Data PDU received from the lower layer is different from the local ID configured in operation 803 and / or operation 805, the SRAP reception portion of the target UE 830 may discard the SRAP Data PDU. The SRAP reception portion of the target UE 830 may remove the header of the SRAP Data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the SL-SRB corresponding to the bearer ID included in the header of the SRAP Data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, the target UE 830 may distinguish between the SL-DRB and the SL-SRB based on the PC5 relay RLC channel through which the SRAP Data PDU was received.

[0321] According to an embodiment, the SRAP transmitting portion of the target UE 830 may determine the UE ID corresponding to the source UE 810 in order to transmit the SRAP SDU received from the upper layer to the source UE 810. The UE ID may be substantially the same as the local ID configured in the SRAP of the target UE 830 in operation 803 and / or operation 805. The SRAP of the target UE 830 may determine the bearer ID based on the SL-SRB identifier received from the upper layer. The SRAP transmitting portion of the target UE 830 may generate an SRAP data PDU by combining the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The target UE 830 may transmit the generated SRAP data PDU to the relay UE 820 via the PC5 relay RLC channel configured to transmit the SRAP data PDU via the SL-SRB.

[0322] According to an embodiment, when relay UE 820 receives an SRAP Data PDU transmitted by target UE 830, the SRAP receiving section of relay UE 820 may deliver the SRAP Data PDU received from the lower layer to the SRAP transmitting section for transmission to source UE 810. The SRAP transmitting section of relay UE 820 may determine the source UE 810 corresponding to the UE ID in the SRAP header. The UE ID may be substantially the same as the local ID configured in the SRAP of relay UE 820 in operations 801, 803, 805, and / or 807. If the UE ID is not configured in the SRAP, relay UE 820 may discard the SRAP Data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 820 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP Data PDU was received. The relay UE 820 may perform transmission to the source UE 810 through a PC5 relay RLC channel configured to transmit the SL-SRB corresponding to the bearer ID of the SRAP header.

[0323] According to an embodiment, when source UE 810 receives an SRAP data PDU transmitted by relay UE 820, if the UE ID included in the header of the SRAP data PDU received from the lower layer is different from the local ID configured in operation 801 or 807, the SRAP reception portion of source UE 810 may discard the SRAP data PDU. The SRAP reception portion of source UE 810 may remove the header of the SRAP data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the SL-SRB corresponding to the bearer ID included in the header of the SRAP data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, source UE 810 may distinguish between an SL-DRB and an SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU has been received.

[0324] Figure 9 A flowchart of a process for establishing an end-to-end (E2E) sidelink data radio bearer (SL-DRB) for a UE-to-UE (U2U) relay and configuring an adaptation layer for the sidelink data radio bearer relay according to an embodiment of the present disclosure is shown.

[0325] refer to Figure 9 According to the embodiment, the source UE 910 and the relay UE 920 may have established a PC5 unicast link, and the relay UE 920 and the target UE 930 may have established a PC5 unicast link. The establishment of each PC5 unicast link may follow Figure 5The source UE 910 and the target UE 930 may have established an end-to-end PC5 unicast link. The establishment of the end-to-end PC5 unicast link may follow Figure 7 or Figure 8 .

[0326] According to an embodiment, the source UE 910 or the target UE 930 may acquire configuration information about the end-to-end SL-DRB, and the acquisition method may be as in the example of [Table 2]. If the source UE 910 or the target UE 930 is serving as a transmitting (Tx) UE, the source UE 910 or the target UE 930 may acquire configuration information about the SL-DRB of the QoS flow corresponding to the data to be transmitted based on one of the three methods of [Table 2], and in operation 901, the source UE 910 or the target UE 930 may deliver the SL-DRB configuration information of the QoS flow to the target UE 930 or the source UE 910 corresponding to the receiving (Rx) UE via PC5-RRC signaling. The SL-DR configuration information to be applied when the receiving UE receives the QoS data flow may be determined by the receiving UE itself. The SL-DRB configuration information that may be included in the PC5-RRC signaling may be as shown in [Table 15].

[0327] [Table 15]

[0328] As an embodiment, in addition to the MAC configuration and PC5 RLC channel configuration for end-to-end SL-DRB transmission in [Table 15], only SDAP and PDCP configuration for SLRB may be transmitted.

[0329] According to an embodiment, in operation 901, in a case where the source UE 910 or the target UE 930 is a receiving UE, if it is determined that the configuration of the PC5-RRC signaling delivered for the end-to-end SL-DRB establishment has been normally applied, the source UE 910 or the target UE 930 may transmit configuration application completion information to the target UE 930 or the source UE 910, which is a sending UE, via PC5-RRC signaling. For example, in a case where the source UE 910 or the target UE 930 is a sending UE, when the completion of applying the end-to-end SL-DRB configuration is received via PC5-RRC signaling, it may be determined that the establishment of the end-to-end SL-DRB has been completed. For example, in a case where the source UE 910 or the target UE 930 is a receiving UE, when the SL-DRB configuration has been received via PC5-RRC signaling and the configuration of the signaling has been normally applied, it may be determined that the establishment of the end-to-end SL-DRB has been completed.

[0330] According to an embodiment, in order to receive and transmit an end-to-end SL-DRB message, if at least one of the following conditions is satisfied, in operation 902, the source UE 910 may transmit PC5-RRC signaling to the relay UE 920 and configure SRAP.

[0331] Condition 1: When at least one end-to-end SL-DRB to be sent to the target UE 930 has been established

[0332] Condition 2: When the PC5 relay RLC channel established between the source UE 910 and the target UE 930 for end-to-end SL-DRB transmission has not been configured

[0333] Condition 3: When SRAP or at least one PC5 relay RLC channel for end-to-end SL-DRB transmission established between the source UE 910 and the target UE 930 has not been configured

[0334] The information that may be included in the information transmitted via PC5-RRC signaling in operation 920 may be at least some of the examples in [Table 16]. Additionally, information for configuration between the relay UE 920 and the target UE 930 may also be included, and at least one of the information elements in [Table 16] may be included.

[0335] [Table 16]

[0336] According to an embodiment, an RLC channel for end-to-end SL-DRB relay transmission may be determined or identified based on PC5 relay RLC channel configuration information between the source UE 910 and the relay UE 920, which configuration information is transmitted in operation 902. As an embodiment, when the SL-DRB ID is indicated in operation 902, the indicated SL-DRB may be transmitted through the indicated PC5 relay RLC channel. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. Figure 7 or Figure 8 An example of determining or identifying the configuration of a PC5 relay RLC channel for end-to-end SL-SRB transmission.

[0337] According to an embodiment, when the relay UE 920 receives the SRAP configuration from the source UE 910 in operation 902, if it is determined that the configuration has been normally applied, then in operation 903, the relay UE 720 may send information indicating that the application of the configuration has been completed to the source UE 910 via PC5-RRC signaling. For example, when the source UE 910 sends the SRAP configuration in operation 902 or receives the SRAP configuration application completion in operation 903, the source UE 910 may determine that the SRAP configuration for the end-to-end SL-DRB with the target UE 930 has been completed. For example, when the relay UE 920 receives the SRAP configuration in operation 902 or sends the SRAP configuration application completion in operation 903, the relay UE 920 may determine that the SRAP configuration between the source UE 910 and the relay UE 820 has been completed.

[0338] According to an embodiment, in order to receive and transmit an end-to-end SL-DRB message, if at least one of the following conditions is satisfied, in operation 904 , the relay UE 920 may transmit PC5-RRC signaling to the target UE 930 and configure SRAP.

[0339] Condition 1: When the source UE 910 has configured SRAP via PC5-RRC signaling in operation 902

[0340] Condition 2: When the SRAP configuration between the source UE 910 and the relay UE 920 has been completed

[0341] In this case, information that may be included in the SRAP configuration information may be some of the examples in [Table 17].

[0342] [Table 17]

[0343] According to an embodiment, an RLC channel for end-to-end SL-DRB relay transmission may be determined or identified based on PC5 relay RLC channel configuration information between the relay UE 920 and the target UE 930, the configuration information being transmitted in operation 904. As an embodiment, when the SL-DRB ID is indicated in operation 904, the indicated SL-DRB may be transmitted through the indicated PC5 relay RLC channel. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. The configuration of the PC5 relay RLC channel for end-to-end SL-SRB transmission may follow Figure 7 or Figure 8 .

[0344] As an embodiment, in operation 904 , the relay UE 920 may transmit the U2U relay configuration to the target UE 930 during the period in which the relay UE 920 transmits PC5-RRC signaling.

[0345] If the source UE 910 delivers information for configuration between the relay UE 920 and the target UE 930 in operation 902, the U2U relay configuration delivered in operation 904 may be configured to be the same as at least one of the information elements (e.g., SL-SRB ID, indicator, or PC5 relay RLC channel configuration information between the UE 920 and the source UE 910) included in the information delivered in operation 902. The PC5 relay RLC channel ID for SL-DRB transmission may be selected by the relay UE 920. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. The configuration of the PC5 relay RLC channel for end-to-end SL-SRB transmission may follow Figure 7 or Figure 8 .

[0346] According to an embodiment, when the target UE 930 receives the SRAP configuration from the relay UE 920 in operation 904, if it is determined that the configuration has been normally applied, the target UE 930 may transmit information indicating that the application of the configuration has been completed to the relay UE 920 via PC5-RRC signaling in operation 905. For example, when the target UE 930 receives the SRAP configuration in operation 904 or transmits "SRAP configuration application complete" in operation 905, the target UE 930 may determine that the SRAP configuration for the end-to-end SL-DRB has been completed. For example, when the relay UE 920 transmits the SRAP configuration in operation 904 or receives "SRAP configuration application complete" in operation 905, the relay UE 920 may determine that the SRAP configuration between the target UE 930 and the relay UE 720 has been completed.

[0347] According to an embodiment, in order to receive and transmit an end-to-end SL-DRB message, if at least one of the following conditions is satisfied, in operation 906 , the target UE 930 may transmit PC5-RRC signaling to the relay UE 920 and configure SRAP.

[0348] Condition 1: When at least one end-to-end SL-DRB to be sent to the source UE 910 has been established

[0349] Condition 2: When the PC5 relay RLC channel established between the source UE 910 and the target UE 930 for end-to-end SL-DRB transmission has not been configured

[0350] Condition 3: When SRAP or at least one PC5 relay RLC channel for end-to-end SL-DRB transmission established between the source UE 910 and the target UE 930 has not been configured

[0351] The information that may be included in the information sent via PC5-RRC signaling may be at least some of the examples in [Table 18]. Additionally, information for configuration between the relay UE 920 and the source UE 910 may also be included, and may include at least one of the information elements in [Table 18].

[0352] [Table 18]

[0353] According to an embodiment, an RLC channel for end-to-end SL-DRB relay transmission may be determined or identified based on PC5 relay RLC channel configuration information between the target UE 930 and the relay UE 920, which configuration information is transmitted in operation 906. As an embodiment, when the SL-DRB ID is indicated in operation 906, the indicated SL-DRB may be transmitted through the indicated PC5 relay RLC channel. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. The configuration of the PC5 relay RLC channel for end-to-end SL-SRB transmission may follow Figure 7 or Figure 8 .

[0354] According to an embodiment, when the relay UE 920 receives the SRAP configuration from the target UE 930 in operation 906, if it is determined that the configuration has been normally applied, the relay UE 820 may transmit information indicating that the application of the configuration has been completed to the target UE 930 via PC5-RRC signaling in operation 907. For example, when the target UE 930 transmits the SRAP configuration in operation 906 or receives the SRAP configuration application completion in operation 907, the target UE 930 may determine that the SRAP configuration for the end-to-end SL-DRB with the source UE 910 has been completed. For example, when the relay UE 920 receives the SRAP configuration in operation 906 or transmits the SRAP configuration application completion in operation 907, the relay UE 920 may determine that the SRAP configuration between the target UE 930 and the relay UE 820 has been completed.

[0355] According to an embodiment, in order to receive and transmit an end-to-end SL-DRB message, if at least one of the following conditions is satisfied, in operation 908 , the relay UE 920 may transmit PC5-RRC signaling to the source UE 910 and configure SRAP.

[0356] Condition 1: When the target UE 930 has configured SRAP via PC5-RRC signaling in operation 906

[0357] Condition 2: When the SRAP configuration between the target UE 930 and the relay UE 920 has been completed

[0358] Information that can be included in the SRAP configuration may include at least some of the examples in [Table 19].

[0359] [Table 19]

[0360] According to an embodiment, an RLC channel for end-to-end SL-DRB relay transmission may be determined or identified based on PC5 relay RLC channel configuration information between the relay UE 920 and the source UE 910, the configuration information being transmitted in operation 908. As an embodiment, when the SL-DRB ID is indicated in operation 908, the indicated SL-DRB may be transmitted through the indicated PC5 relay RLC channel. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. The configuration of the PC5 relay RLC channel for end-to-end SL-SRB transmission may follow Figure 7 or Figure 8 .

[0361] As an embodiment, in operation 908 , the relay UE 920 may transmit the U2U relay configuration to the source UE 910 during the period in which the relay UE 920 transmits the PC5-RRC signaling.

[0362] If the target UE 930 delivers information for configuration between the relay UE 920 and the source UE 910 (e.g., U2U relay configuration) in operation 906, at least one piece of information included in the configuration information transmitted in operation 906 may be configured to be substantially the same as the U2U relay configuration transmitted in operation 908. The PC5 relay RLC channel ID for SL-DRB transmission may be selected by the relay UE 920. In this case, if the end-to-end SL-DRB ID is 1, 2, 3, or 4, the PC5 relay RLC channel for end-to-end SL-DRB transmission and the PC5 relay RLC channel for end-to-end SL-SRB transmission may be different. The configuration of the PC5 relay RLC channel for end-to-end SL-SRB transmission may follow Figure 7 or Figure 8 .

[0363] According to an embodiment, when the source UE 910 receives the SRAP configuration from the relay UE 920 in operation 908, if it is determined that the configuration has been normally applied, the source UE 910 may transmit information indicating that the application of the configuration has been completed to the relay UE 920 via PC5-RRC signaling in operation 909. For example, when the source UE 910 receives the SRAP configuration in operation 908 or transmits the SRAP configuration application completion in operation 909, the source UE 910 may determine that the SRAP configuration for the end-to-end SL-DRB has been completed. For example, when the relay UE 920 transmits the SRAP configuration in operation 908 or receives the SRAP configuration application completion in operation 909, the relay UE 920 may determine that the SRAP configuration between the source UE 910 and the relay UE 920 has been completed.

[0364] According to an embodiment, the SRAP transmission portion of the source UE 910 may determine the UE ID corresponding to the target UE 930 in order to transmit the SRAP SDU received from the upper layer to the target UE 930. The UE ID may be substantially the same as the local ID configured in the SRAP of the source UE 910 in operation 902 and / or operation 908. The SRAP of the source UE 910 may determine the bearer ID as the end-to-end SL-DRB identifier received from the upper layer or a value one less than the end-to-end SL-DRB identifier. The SRAP transmission portion of the source UE 910 may generate an SRAP data PDU by combining the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The source UE 910 may transmit the generated SRAP data PDU to the relay UE 920 via the PC5 relay RLC channel configured to transmit the end-to-end SL-SRB.

[0365] According to an embodiment, when relay UE 920 receives an SRAP Data PDU transmitted by source UE 910, the SRAP receiving section of relay UE 920 may deliver the SRAP Data PDU received from the lower layer to the SRAP transmitting section for transmission to target UE 930. The SRAP transmitting section of relay UE 920 may determine the target UE 930 corresponding to the UE ID in the SRAP header. The UE ID may be substantially the same as the local ID configured in the SRAP of relay UE 820 in operations 902, 904, 906, and / or 908. If the UE ID is not configured in the SRAP, relay UE 920 may discard the SRAP Data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 920 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP Data PDU was received. The relay UE 920 may perform transmission to the target UE 930 through a PC5 relay RLC channel configured to transmit an end-to-end SL-DRB corresponding to the bearer ID of the SRAP header.

[0366] According to an embodiment, when the target UE 930 receives an SRAP data PDU transmitted by the relay UE 920, if the UE ID included in the header of the SRAP data PDU received from the lower layer is different from the local ID configured in operation 904 and / or operation 906, the SRAP reception portion of the target UE 930 may discard the SRAP data PDU. The SRAP reception portion of the target UE 930 may remove the header of the SRAP data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the end-to-end SL-DRB corresponding to the bearer ID included in the header of the SRAP data PDU or a value greater than the bearer ID by 1. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, the target UE 930 may distinguish between an SL-DRB and an SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU was received.

[0367] According to an embodiment, the SRAP transmitting portion of the target UE 930 may determine the UE ID corresponding to the source UE 910 in order to transmit the SRAP SDU received from the upper layer to the source UE 910. The UE ID may be substantially the same as the local ID configured in the SRAP of the target UE 930 in operation 904 or 906. The SRAP of the target UE 930 may determine the bearer ID as the end-to-end SL-DRB identifier received from the upper layer or a value one less than the end-to-end SL-DRB identifier. The SRAP transmitting portion of the target UE 930 may generate an SRAP data PDU by combining the SRAP SDU with the SRAP header including the determined UE ID and bearer ID. The target UE 930 may transmit the generated SRAP data PDU to the relay UE 920 via the PC5 relay RLC channel configured to transmit the end-to-end SL-SRB.

[0368] According to an embodiment, when relay UE 920 receives an SRAP data PDU transmitted by target UE 930, the SRAP receiving section of relay UE 920 may deliver the SRAP data PDU received from the lower layer to the SRAP transmitting section for transmission to source UE 910. The SRAP transmitting section of relay UE 920 may determine the source UE 910 corresponding to the UE ID in the SRAP header. The UE ID may be substantially the same as the local ID configured in the SRAP of relay UE 920 in operations 902, 904, 906, and / or 908. If the UE ID is not configured in the SRAP, relay UE 920 may discard the SRAP data PDU. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, relay UE 920 may distinguish between a SL-DRB and a SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU was received. The relay UE 920 may perform transmission to the source UE 910 through a PC5 relay RLC channel configured to transmit an end-to-end SL-DRB corresponding to the bearer ID of the SRAP header.

[0369] According to an embodiment, when source UE 910 receives an SRAP data PDU transmitted by relay UE 920, if the UE ID included in the header of the SRAP data PDU received from the lower layer is different from the local ID configured in operation 902 and / or operation 908, the SRAP reception portion of source UE 910 may discard the SRAP data PDU. The SRAP reception portion of source UE 910 may remove the header of the SRAP data PDU received from the lower layer and deliver the SRAP SDU to the PDCP of the end-to-end SL-DRB corresponding to the bearer ID included in the header of the SRAP data PDU or a value greater than the bearer ID by 1. If the bearer ID included in the SRAP header is 0, 1, 2, or 3, source UE 910 may distinguish between an SL-DRB and an SL-SRB based on the PC5 relay RLC channel through which the SRAP data PDU was received.

[0370] Figure 10 The internal structure of a base station according to an embodiment of the present disclosure is shown.

[0371] refer to Figure 10 The base station may include a transceiver 1010, a controller 1020, and / or a storage device 1030. The transceiver 1010, the controller 1020, and / or the storage device 1030 may operate according to the above-described communication method of the base station. The network device may also correspond to the structure of the base station. However, the components of the base station are not limited to the above examples. For example, the base station may include a greater or lesser number of components than those described above. For example, the base station may include the transceiver 1010 and the controller 1020. Furthermore, the transceiver 1010, the controller 1020, and / or the storage device 1030 may be implemented in the form of a single chip.

[0372] The base station of the present disclosure may correspond to Figure 1 Base station 130, Figure 2 Base station 230 and / or Figure 3 Base station 330 in.

[0373] The transceiver 1010 generally refers to a base station receiver and a base station transmitter, and can transmit and receive signals with a UE, other base stations, and other network devices. The transmitted and received signals may include control information and data. The transceiver 1010 can transmit, for example, system information, synchronization signals, or reference signals to the UE. To this end, the transceiver 1010 may include an RF transmitter configured to up-convert and amplify the frequency of transmitted signals, an RF receiver configured to perform low-noise amplification and down-convert the frequency of received signals, and the like. However, this is merely an embodiment of the transceiver 1010, and the components of the transceiver 1010 are not limited to an RF transmitter and an RF receiver. The transceiver 1010 may include a wired or wireless transceiver and may include various components for transmitting and receiving signals. In addition, the transceiver 1010 can receive signals via a communication channel (e.g., a wireless channel), output signals to the controller 1020, and transmit signals output from the controller 1020 via the communication channel. In addition, the transceiver 1010 may receive communication signals, output communication signals to the processor, and transmit the signals output from the processor to the UE, other base stations, or other network entities through a wired / wireless network.

[0374] The storage device 1030 may store programs and data necessary for the operation of the base station. Furthermore, the storage device 1030 may store control information or data included in signals acquired by the base station. The storage device 1030 may include a storage medium such as ROM, RAM, a hard disk, a CD-ROM, and a DVD, or a combination of these storage media. Furthermore, the storage device 1030 may store at least one of information transmitted / received by the transceiver 1010 and information generated by the controller 1020.

[0375] As used herein, controller 1020 can be defined as a circuit, an application-specific integrated circuit, or at least one processor. Processors may include a communication processor (CP) that performs communication control and an application processor (AP) that controls upper layers (such as application programs). Controller 1020 may control the overall operation of the base station according to the embodiments presented in this disclosure. For example, controller 1020 may control the signal flow between corresponding blocks to perform operations according to the above-described flowchart.

[0376] Figure 11 The structure of a UE according to an embodiment of the present disclosure is shown.

[0377] refer to Figure 11, the UE may include a transceiver 1110, a controller 1120, and a storage device 1130. The transceiver 1110, the controller 1120, and the storage device 1130 may operate according to the above-described communication method of the UE. However, the components of the UE are not limited to the above-described examples. For example, the UE may include a greater or lesser number of components than those described above. For example, the UE may include the transceiver 1110 and the controller 1120. Furthermore, the transceiver 1110, the controller 1120, and the storage device 1130 may be implemented in the form of a single chip.

[0378] Figure 11 The UE of the present disclosure may correspond to Figure 1 to Figure 1 2, the remote UE 210, the relay UE (eg, Figure 2 ), the source UE (e.g., Figure 4 ) or a target UE (e.g., Figure 4 430 in the target UE).

[0379] The transceiver 1110 generally refers to a UE receiver and a UE transmitter, and can transmit and receive signals with a base station, other UEs, and other network entities. Signals transmitted and received with a base station may include control information and data. The transceiver 1110 may receive, for example, system information, synchronization signals, or reference signals from the base station. To this end, the transceiver 1110 may include an RF transmitter configured to up-convert and amplify the frequency of a transmitted signal, an RF receiver configured to perform low-noise amplification and down-convert the frequency of a received signal, and the like. However, this is merely an embodiment of the transceiver 1110, and the components of the transceiver 1110 are not limited to an RF transmitter and an RF receiver. In addition, the transceiver 1110 may include a wired / wireless transceiver and may include various components for transmitting and receiving signals. In addition, the transceiver 1110 may receive signals via a radio channel, output signals to the controller 1120, and transmit signals output from the controller 1120 via a wireless channel. In addition, the transceiver 1110 may receive a communication signal, output the communication signal to the processor, and transmit the signal output from the processor to a network entity through a wired / wireless network.

[0380] The storage device 1130 may store programs and data necessary for the operation of the UE. In addition, the storage device 1130 may store control information or data included in the signal acquired by the UE. The storage device 1130 may include a storage medium such as ROM, RAM, hard disk, CD-ROM, DVD, or a combination of storage media.

[0381] As used herein, controller 1120 can be defined as a circuit, an application-specific integrated circuit, or at least one processor. Processors may include a communication processor (CP) that performs communication control and an application processor (AP) that controls upper layers (such as application programs). Controller 1120 may control the overall operation of the UE according to the embodiments presented in this disclosure. For example, controller 1120 may control the signal flow between corresponding blocks to perform operations according to the above-described flowchart.

[0382] The methods disclosed in the claims or the methods according to the embodiments described in the specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

[0383] When the method is implemented by software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium may be configured for execution by one or more processors within an electronic device. At least one program includes instructions that cause the electronic device to perform the methods defined in the appended claims and / or disclosed herein according to various embodiments of the present disclosure.

[0384] These programs (software modules or software) may be stored in non-volatile memory, including random access memory and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, compact disc-ROMs (CD-ROMs), digital versatile discs (DVDs) or other types of optical storage devices, or magnetic tape cassettes. Alternatively, any combination of some or all of these may form the memory in which the programs are stored. In addition, multiple such memories may be included in the electronic device.

[0385] Furthermore, the program may be stored on an attachable storage device that can be accessed by the electronic device via a communication network such as the Internet, an intranet, a local area network (LAN), a wide area LAN (WLAN), and a storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device via an external port. Alternatively, a separate storage device on a communication network can access the portable electronic device.

[0386] In the above detailed embodiments of the present disclosure, the elements included in the present disclosure are expressed in the singular or plural, depending on the detailed embodiment presented. However, for ease of description, the singular form or plural form is appropriately selected for the situation presented, and the present disclosure is not limited to elements expressed in the singular or plural. Therefore, an element expressed in the plural may also include a single element, or an element expressed in the singular may also include multiple elements.

[0387] Although specific embodiments have been described in the detailed description of the present disclosure, various modifications and changes may be made thereto without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be defined as being limited to the embodiments set forth herein, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a relay UE for UE-to-UE U2U sidelink communication in a wireless communication system, the method comprising: Get configuration information about the Sidelink Relay Adaptation Protocol (SRAP). as well as Based on the configuration information, receiving an SRAP protocol data unit (PDU) from the first UE by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs), The SRAP PDU is received by the relay UE using a radio link control RLC channel shared by the multiple SL SRBs.

2. The method according to claim 1, in, Each of the plurality of SL SRBs has a designated bearer ID, The RLC channel corresponds to a logical channel identifier LCID designated for the U2U sidelink communication, and The method comprises: Based on a first bearer ID included in a header of the SRAP PDU received through the RLC channel, it is identified that the SRAP PDU has been received through a first SL SRB corresponding to the first bearer ID among the plurality of SL SRBs.

3. The method according to claim 1, further comprising: receiving information about a SL data radio bearer (DRB) of the relay UE from the first UE, The information about the SL DRB includes at least one of a layer 2 L2 identification ID of a second UE performing the U2U sidelink communication with the first UE or end-to-end E2E quality of service (QoS) information of the SL DR, and The E2E QoS information includes information about a packet delay budget (PDB).

4. The method according to claim 1, further comprising: receiving an end-to-end E2E message for a SL data radio bearer (DRB) from the first UE; as well as sending the E2E message for the SL DRB to a second UE performing the U2U sidelink communication with the first UE, The E2E message for the SL DRB includes at least one of the layer 2 L2 identification ID of the first UE, the local ID of the relay UE, the SL DRB ID, the RLC channel ID for the SL DRB, or the RLC channel configuration information between the relay UE and the second UE, and In which, when the first UE is in one of the radio resource control RRC idle state, RRC inactive state and out-of-coverage OOC state, the information about the SL DRB is based on pre-configured information or system information block SIB.

5. A relay UE for UE-to-UE U2U sidelink communication in a wireless communication system, the relay UE comprising: transceiver; as well as a controller coupled with the transceiver, Wherein, the controller is configured as follows: Obtaining configuration information about the Sidelink Relay Adaptation Protocol (SRAP); and receiving a SRAP protocol data unit (PDU) from the first UE by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs) based on the configuration information, and The SRAP PDU is received by the relay UE using a radio link control RLC channel shared by the multiple SL SRBs.

6. The relay UE according to claim 5, in, Each of the plurality of SL SRBs has a designated bearer ID, The RLC channel corresponds to a logical channel identifier LCID designated for the U2U sidelink communication, and The controller is configured to: based on a first bearer ID included in a header of the SRAP PDU received through the RLC channel, identify that the SRAP PDU has been received through a first SLSRB among the multiple SL SRBs corresponding to the first bearer ID.

7. The relay UE according to claim 5, in, The controller is configured to receive information about a SL data radio bearer (DRB) of the relay UE from the first UE, The information about the SL DRB includes at least one of a layer 2 L2 identification ID of a second UE performing the U2U sidelink communication with the first UE or end-to-end E2E quality of service (QoS) information of the SL DR, and The E2E QoS information includes information about a packet delay budget (PDB).

8. The relay UE according to claim 5, wherein: The controller is configured as follows: Receiving an end-to-end E2E message for a SL data radio bearer (DRB) from the first UE; and sending the E2E message for the SL DRB to a second UE performing the U2U sidelink communication with the first UE, The E2E message for the SL DRB includes at least one of the layer 2 L2 identification ID of the first UE, the local ID of the relay UE, the SL DRB ID, the RLC channel ID for the SL DRB, or the RLC channel configuration information between the relay UE and the second UE, and In which, when the first UE is in one of the radio resource control RRC idle state, RRC inactive state and out-of-coverage OOC state, the information about the SL DRB is based on pre-configured information or system information block SIB.

9. A method performed by a first user equipment (UE) in a wireless communication system, the method comprising: Get configuration information about the Sidelink Relay Adaptation Protocol (SRAP). as well as Based on the configuration information, sending a SRAP protocol data unit (PDU) to a relay UE for UE-to-UE U2U sidelink communication by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs), The SRAP PDU is sent to the relay UE by using a radio link control RLC channel shared by the multiple SL SRBs.

10. The method according to claim 9, in, Each of the plurality of SL SRBs has a designated bearer ID, The RLC channel corresponds to a logical channel identifier LCID designated for the U2U sidelink communication, and The first bearer ID corresponding to the first SL SRB among the multiple SL SRBs is included in the header of the SRAP PDU.

11. The method according to claim 9, comprising: Sending information about the SL data radio bearer (DRB) of the relay UE to the relay UE, The information about the SL DRB includes at least one of a layer 2 L2 identification ID of a second UE performing the U2U sidelink communication with the first UE or end-to-end E2E quality of service (QoS) information of the SL DR, and The E2E QoS information includes information about a packet delay budget (PDB).

12. The method according to claim 9, further comprising: Sending an end-to-end E2E message for a SL data radio bearer (DRB) to the relay UE, The E2E message for the SL DRB includes at least one of the layer 2 L2 identification ID of the first UE, the local ID of the relay UE, the SL DRB ID, the RLC channel ID for the SL DRB, or the RLC channel configuration information between the relay UE and the second UE performing the U2U sidelink communication with the first UE, and In which, when the first UE is in one of the radio resource control RRC idle state, RRC inactive state and out-of-coverage OOC state, the information about the SL DRB is based on pre-configured information or system information block SIB.

13. A first user equipment (UE) in a wireless communication system, the first UE comprising: transceiver; as well as a controller coupled with the transceiver, Wherein, the controller is configured as follows: Obtaining configuration information about the Sidelink Relay Adaptation Protocol (SRAP); and Based on the configuration information, sending a SRAP protocol data unit (PDU) to a relay UE for UE-to-UE U2U sidelink communication by using at least one of a plurality of sidelink signaling radio bearers (SL SRBs); and The SRAP PDU is sent to the relay UE by using a radio link control RLC channel shared by the multiple SL SRBs.

14. The first UE according to claim 13, in, The controller is configured to: send information about a SL data radio bearer (DRB) of the relay UE to the relay UE, The information about the SL DRB includes at least one of a layer 2 L2 identification ID of a second UE performing the U2U sidelink communication with the first UE or end-to-end E2E quality of service (QoS) information of the SL DR, and The E2E QoS information includes information about a packet delay budget (PDB).

15. The first UE according to claim 13, in, The controller is configured to: send an end-to-end E2E message for a SL data radio bearer DRB to the relay UE, The E2E message for the SL DRB includes at least one of the layer 2 L2 identification ID of the first UE, the local ID of the relay UE, the SL DRB ID, the RLC channel ID for the SL DRB, or the RLC channel configuration information between the relay UE and the second UE performing the U2U sidelink communication with the first UE, and In which, when the first UE is in one of the radio resource control RRC idle state, RRC inactive state and out-of-coverage OOC state, the information about the SL DRB is based on pre-configured information or system information block SIB.

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